The terraces of Badab-e Surt were formed mainly by water flowing down from hot mineral springs. Their yellowish and reddish pools are characteristic. wikipedia.org/Badab-e_Surt

At 1642 metres, Lake Baikal is the deepest lake on Earth. It is also the largest freshwater lake by volume and, at an estimated 25–30 million years, the oldest lake in the world. wikipedia.org/Baikalsee

The mineral-rich water that springs from the source here and the limestone rock offer enough grip to climb the ‘sticky waterfalls’ with ease.

On Bohol lie the Chocolate Hills – more than 1200 dome-shaped, grass-covered hills that turn brown in the dry season. wikipedia.org/Chocolate_Hills

The Lut Desert is one of the hottest and driest places on Earth. Iconic are the rock formations in the west, the so-called ‘sand castles’. wikipedia.org/Dasht-e_Lut

Gosu Cave contains more than 120 stalactites and stalagmites and is home to over 20 animal species. In prehistoric times it was probably also inhabited by humans. wikipedia.org/Gosu_Cave

Heaven Lake is a crater lake on Paektu Mountain. Its location at an altitude of more than 2000 metres makes it one of the coldest lakes in the world. wikipedia.org/Himmelssee

The Jeita Grotto consists of a series of connected caves, the largest of which is more than 100 metres high. It also holds the largest stalactite ever found. wikipedia.org/Jeita-Grotte

The 20-metre-high rock tower stands off the island of Khao Phing Kan, which rises just as steeply. Both became world-famous through the James Bond film ‘The Man with the Golden Gun’. wikipedia.org/Khao_Phing_Kan

Kow Ata is an underground thermal lake about 60 metres below the cave entrance. The cave is also home to the largest bat colony in Central Asia. wikipedia.org/Kow-Ata

The Lena Pillars rise 150–300 metres along the southern bank of the Lena, over a length of about 80 kilometres. The huge rock needles were formed around 500 million years ago. wikipedia.org/Lena_(Arktischer_Ozean)

Makhtesh Ramon lies in the Negev Desert. The crater is about 500 metres deep and was formed by erosion alone, making it the largest erosion crater of its kind on Earth. wikipedia.org/Machtesch_Ramon

Mount Everest is the highest mountain on Earth above sea level. In Tibetan the mountain is known as Chomolungma, in Nepali as Sagarmatha. wikipedia.org/Mount_Everest

Pamukkale is famous for its thermal springs, which formed the unique white limestone terraces that have become a popular tourist attraction. wikipedia.org/Pamukkale

Pantai Merah, the pink beach, lies on the east of Komodo. Its colour comes from white sand mixed with red foraminifera, tiny single-celled organisms.

In the national park of the same name, the Cabayugan flows for about 8 kilometres through St. Paul’s Underground River Cave. wikipedia.org/Puerto-Princesa-Subterranean-River-Nationalpark

Red Beach owes its name to the reddish seepweed growing in the marshy Liaohe river delta near Panjin. Most of the area is a nature reserve closed to the public. wikipedia.org/Red_Beach_(Panjin)

Hundreds of rock pinnacles near Göreme in Cappadocia form a fairytale landscape, from free-standing, minaret-like ‘fairy chimneys’ to large wave-like formations. wikipedia.org/Kappadokien

With more than 400 mud volcanoes, Azerbaijan holds over half of these unusual mounds, often close to oil and gas fields. wikipedia.org/Schlammvulkane_in_Aserbaidschan

Spread over an area of more than 300 square kilometres, the pointed limestone rocks of Shilin create the impression of a stone forest. wikipedia.org/Stone_Forest

South of Kyrgyzstan’s largest lake, Issyk-Kul, lies Skazka Canyon, the fairytale canyon, with its multicoloured rock and astonishing formations.

Covering about 10000 square kilometres around the Ganges delta between India and Bangladesh, the Sundarbans form the largest mangrove forest on Earth. wikipedia.org/Sundarbans

The shores of the Dead Sea are the lowest point on the Earth’s surface. It is also the deepest salt lake and one of the saltiest bodies of water on the planet. wikipedia.org/Totes_Meer

This hollow lies in the western part of the Uvs Nuur Basin. Its varied landscape of lakes, marshes, steppe and mountains is home to many animal and plant species. wikipedia.org/Uws-Nuur-Becken

Largely unknown to the public until 2016, the granite rock towers of Ulakhan-Sis in northern Yakutia fascinate with a wealth of astonishing shapes. wikipedia.org/Ulachan-Sis_(Jana-Indigirka-Tiefland)

In Ha Long Bay, the ‘bay of the descending dragon’, around 2000 limestone rocks large and small rise from the water. Many of the caves are accessible only at low tide. wikipedia.org/Hạ_Long_Bay

More than 3000 steep limestone pillars, some over 200 metres high, shape the landscape of Wulingyuan, which is also rich in streams and pools. wikipedia.org/Wulingyuan

Yanar Dag is a continuously burning natural gas fire on the coast of the Caspian Sea. The flames can reach heights of up to 10 metres. wikipedia.org/Yanar_Dağ

Reddish and yellowish rocks, on which erosion has left huge wave-like patterns, shape Yangykala Canyon on the western edge of the Karakum Desert. wikipedia.org/Yangykala-Schlucht

The rocks of the Zhangye Danxia Geopark are striking above all for their variety of colours, arranged in bold stripes. wikipedia.org/Zhangye-Danxia-Geopark

Stretching more than 2000 kilometres, the nearly 3000 individual reefs of the Great Barrier Reef make up the largest coral reef system on Earth. wikipedia.org/Great_Barrier_Reef

Kazumura Cave lies on the Kīlauea volcano on Hawaii’s Big Island. At 68 kilometres it is the longest lava tube on Earth, and at 1100 metres the deepest. wikipedia.org/Kazumura_Cave

On Middle Island off Australia’s south coast lies the pink Lake Hillier, whose unusual colour is caused by a species of algae found there. wikipedia.org/Lake_Hillier

The 14-kilometre fjord on New Zealand’s South Island fascinates with pyramid-like peaks rising from its shores, numerous waterfalls and a rich wildlife. wikipedia.org/Milford_Sound

In Nambung National Park thousands of limestone pillars in a great variety of shapes rise from the yellowish sand. The area only became widely known in 1967. wikipedia.org/The_Pinnacles_(Western_Australia)

Erosion of the cliffs left these pointed limestone stacks standing in the sea. There were originally only eight of them, one of which has since collapsed. wikipedia.org/Twelve_Apostles_(Australien)

Uluru / Ayers Rock is one of Australia’s best-known landmarks. The changing colours of the rock at dawn and dusk are a natural spectacle in their own right. wikipedia.org/Uluru

The Turda Gorge offers a unique natural environment with more than 1000 plant species and over 50 species of vertebrates. wikipedia.org/Cheile_Turzii

Of the many sea cliffs along Ireland’s coast, the Cliffs of Moher, stretching over 14 kilometres, are the most famous. In the north they reach heights of more than 200 metres. wikipedia.org/Cliffs_of_Moher

From the air the Creux du Van looks like a giant horseshoe print. The 150-metre-deep semicircle lies in the Val de Travers on the border between the cantons of Neuchâtel and Vaud. wikipedia.org/Creux_du_Van

With their natural arches and the 70-metre-high needle L’Aiguille, the chalk cliffs of Étretat are among the most famous and most beautiful coastal formations of their kind. wikipedia.org/Étretat

Fingal’s Cave on the Scottish island of Staffa has been a popular destination for centuries, above all because of its striking hexagonal basalt columns. wikipedia.org/Fingal’s_Cave

On the steep shores of the Geirangerfjord, maritime scenery gives way directly to alpine landscape. The varied terrain and relatively mild climate make the fjord a unique natural area. wikipedia.org/Geirangerfjord

Around 40000 basalt columns, formed some 60 million years ago, shape this stretch of the Northern Irish coast at the Giant’s Causeway. wikipedia.org/Giant’s_Causeway

The gorge through which the turquoise River Verdon winds is a good 20 kilometres long and up to 700 metres deep, making it one of the largest canyons in Europe. wikipedia.org/Verdonschlucht

The unusual deep-blue colour of the water in the Blue Grotto is due to sunlight entering the cave from below the surface, reflected through the water. wikipedia.org/Blaue_Grotte_(Capri)

The Benagil cave was shaped into a dome-like vault by water, wind and weather. This has made it the best-known cave on the Algarve. wikipedia.org/Benagil

The white chalk cliffs on Rügen, Germany’s largest island, are the most famous landmark of Jasmund National Park, which at 30 square kilometres is the country’s smallest national park. wikipedia.org/Kreidefelsen_auf_Rügen

The Manpupuner rocks on the western side of the Urals consist of seven striking stone towers, which is why they are also known as the Seven Strong Men. wikipedia.org/Manpupunjor-Felsen

In Plitvice Lakes National Park more than a dozen lakes are linked across several terraces by a multitude of waterfalls in spectacular fashion. wikipedia.org/Nationalpark_Plitvicer_Seen

A series of astonishingly shaped rock pillars, some more than ten metres high and known as raukar, can be found on the Baltic island of Gotland and some of its neighbouring islands. wikipedia.org/Rauk

Rich deposits of metal ore in the region give the Río Tinto its striking reddish colour along a stretch of about 50 kilometres. wikipedia.org/R%C3%ADo_Tinto

The multicoloured dripstones in the Saalfeld Fairy Grottoes create the impression of a fantasy landscape with countless towers and castles. wikipedia.org/Feengrotten

The cliffs of the Scala dei Turchi on the south coast of Sicily, made of white marl, look like a giant rock staircase. wikipedia.org/Scala_dei_Turchi

Hexagonal basalt columns define this canyon. Originally under water, they came to the surface when the river was dammed. wikipedia.org/Stuðlagil

Covering almost 8000 square kilometres, Vatnajökull is Europe’s second-largest glacier. In places the ice is nearly a kilometre thick. wikipedia.org/Vatnajökull

Crater Lake formed after the collapse of the volcano Mount Mazama – the deepest lake in the USA, fascinating for its clear, deep-blue water. wikipedia.org/Crater_Lake

Astonishing rock towers and the greatest concentration of natural stone arches on Earth were formed over the centuries by erosion in what is now Arches National Park. wikipedia.org/Devils_Garden

Fly Geyser was created by accident through faulty drilling for geothermal energy. Since then it has grown to a height of 1.5 metres. wikipedia.org/Fly_Geyser

The largest hot spring in the USA was not discovered until 1871. It displays all the colours of the rainbow, produced by microorganisms in the water. wikipedia.org/Grand_Prismatic_Spring

The rock formations in Oaxaca resemble two petrified waterfalls, formed over thousands of years by deposits from mineral-rich water. wikipedia.org/Hierve_el_Agua

Named after the Hoh tribe of Native Americans, this temperate rainforest is the largest in the USA. Some of its trees reach heights of almost 100 metres. wikipedia.org/Hoh-Regenwald

The Bay of Fundy between Nova Scotia, New Brunswick and Maine has one of the greatest tidal ranges on Earth. It is also home to some astonishing rock formations. wikipedia.org/Hopewell_Rocks

At Horseshoe Bend, one of the most famous parts of the Grand Canyon, the Colorado River has carved a 300-metre-deep horseshoe-shaped gorge. wikipedia.org/Horseshoe_Bend_(Arizona)

The Yucatán Peninsula is said to have more than 6000 so-called cenotes, water-filled sinkholes. The circular, 50-metre-deep Ik Kil is one of the best known. wikipedia.org/Ik_Kil

Mineral deposits from the hot springs in Yellowstone National Park have built up a variety of terraces around them over millions of years. wikipedia.org/Mammoth_Hot_Springs

The Mendenhall Glacier is known among other things for its ice caves, which keep forming here only to disappear again later. wikipedia.org/Mendenhall-Gletscher

Huge towers of reddish rock, from spectacular pinnacles to massive mesas, rise up to 300 metres in Monument Valley. wikipedia.org/Monument_Valley

At the foot of the peaks in the Valley of the Ten Peaks lies the picturesque Moraine Lake, whose water has the greenish tint typical of glacial lakes. wikipedia.org/Moraine_Lake

Measured by flow rate, the Canadian falls of Niagara are the largest waterfalls in North America. Because of their semicircular shape they are also known as the Horseshoe Falls. wikipedia.org/Niagarafälle

The mineral richness of this salt lake leads to the formation of differently coloured pools, which appear as spots. wikipedia.org/Spotted_Lake

Diverse vegetation in the riverbed gives the Caño Cristales its varied colours, which is why it is also called the River of Five Colours or the Liquid Rainbow. wikipedia.org/Caño_Cristales

Spread over three kilometres, more than 250 individual falls of up to 82 metres together form the Iguazú Falls, the largest waterfall system on Earth. wikipedia.org/Iguazú-Wasserfälle

Kaieteur Falls is one of the highest single-drop waterfalls and at the same time has one of the greatest flow rates, making it one of the most powerful waterfalls on Earth. wikipedia.org/Kaieteur-Fälle

On the shores of Lago General Carrera lies a series of marble caves formed over the past 6000 years, among them the monumental Catedral de Mármol. wikipedia.org/Capilla_de_Mármol

The Gruta do Janelão is a cave in Cavernas do Peruaçu National Park. The Rio Peruaçu flows through it, and the play of light at its openings is impressive. wikipedia.org/Cavernas_do_Peruaçu

The Monturaqui crater was formed by the impact of an iron meteorite some 500000 to 800000 years ago. It has a diameter of around 450 metres and is about 30 metres deep. wikipedia.org/Monturaqui

The Perito Moreno Glacier is part of the Southern Patagonian Ice Field, the largest glacial area in the southern hemisphere. Its towering ice front on Lago Argentino is especially spectacular. wikipedia.org/Perito-Moreno-Gletscher

Lake Titicaca is the largest lake in South America. At an altitude of more than 3500 metres, and despite heavy pollution, it is home to more than 500 aquatic species. wikipedia.org/Titicacasee

The Galápagos Islands are world-famous for their unique and diverse flora and fauna. The islands were created by volcanic activity, which still shapes their nature today. wikipedia.org/Galapagosinseln

On the coast of Maranhão lies the unique dune landscape of Lençóis Maranhenses, made up of fixed and shifting dunes with lagoons in between. wikipedia.org/Lençóis_Maranhenses

At a good 10000 square kilometres, the Salar de Uyuni is the largest salt flat on Earth. The inhospitable expanse forms an almost perfectly level surface. wikipedia.org/Salar_de_Uyuni

At 979 metres, Salto Ángel on the Auyán-tepui mountain is the highest waterfall on Earth. Its indigenous name is Kerepakupai Vená – the waterfall of the deepest place. wikipedia.org/Salto_Ángel