The Crystal Cave of Skaftafell is formed where the Vatnajökull Ice Cap meets the Icelandic coast.
It's the largest hot spring in the United States. The colors of Yellowstone’s Grand Prismatic Spring are caused by bacteria and microbes growing around the water’s edge.
These gypsum crystals in the Naica Mine were formed over 500,000 years in underground hot springs. Unfortunately, the caves are closed to the public (as they are super toxic and dangerous).
Also known as Ayer’s Rock, Uluru is a sandstone rock formation that’s one of Australia’s most recognizable landmarks.
All of Hawaii was formed by volcanoes, but there are still three active volcanoes on the Big Island, which means the landmass is still growing.
Aogashima is a volcano about 220 miles south of Tokyo. Though it hasn’t erupted in over 200 years, it is still considered active.
Salar de Uyuni is the world’s largest salt flat, and is also one of Bolivia’s most visited tourist sites.
The Wave is a sandstone structure on the border of Arizona and Utah. Access is limited by a permitting system.
The stunning Mount Roraima lies at the border of three countries: Brazil, Guyana, and Venezuela.
Caño Cristales, Colombia
Caño Cristales is known as one of the most colorful rivers in the world. The colors are caused by a small plants in the river.
Giant's Causeway, Northern Ireland
These basalt columns on the coast of Northern Ireland were formed by lava during the Paleocene Epoch.
Glow Worm Cave, New Zealand
Glow worms (actually insects) are bioluminescent animals common to New Zealand and Australia. A number of caves are noted for their presence.
Ha Long Bay, Vietnam
The ethereal Ha Long Bay in Northern Vietnam has over 1,600 monolithic limestone islands.
Iguazu Falls, Brazil and Argentina
Iguazu Falls, sitting on the border of Argentina and Brazil, has been named one of the New Seven Wonders of Nature.
Arches National Park, Utah
This is the famous “Delicate Arch” in Arches National Park. There are dozens more arches and other unique geological formations in the park.
Great Blue Hole, Belize
Belize’s famous Great Blue Hole is actually a sinkhole. It’s considered an excellent diving spot.
Aurora borealis
Aurora borealis, or the Northern Lights, are the result of the collision of charged particles with our atmosphere. They are most visible at high northern latitudes.
Ice canyon, Greenland
Scientists have recently discovered a “new grand canyon” underneath Greenland’s ice.
Grand Canyon, Arizona
The incredible Grand Canyon has been formed over the course of 2 billion years by erosion caused by the Colorado River.
Zhangye Danxia Landform, China
Danxia landforms are relatively common in southern China, and are the result of eroding sandstone.
Mendenhall Ice Caves, Alaska
These ice caves lie underneath the Mendenhall Glacier near Juneau, Alaska.
Pamukkale, Turkey
Pamukkale is a Turkish hot springs with natural terraces formed by minerals deposited by the water.
Shifen Waterfall, Taiwan
The Shifen Waterfall on Taiwan’s Keelung River is the largest waterfall in Taiwan.
The Green Bridge of Wales
The Green Bridge is a natural arch that lies on the Pembrokeshire coast in the southwest of Wales.
Antelope Canyon, Arizona
Arizona’s Antelope Canyon is formed by the erosion of sandstone caused by flash floods. It’s the most visited slot canyon in the Southwest.
Rock Pinnacles, Gunung Mulu National Park, Malaysia
In Gunung Mulu National Park, Malaysian Borneo, these rock pinnacles are surrounded by rainforest.
Blue Grotto, Malta
Malta’s Blue Grotto, a series of sea caves, is a favorite among tourists, snorkelers, and cliff-jumpers.
Torres del Paine, Chile
Torres del Paine National Park, in Chilean Patagonia, is best known for these three towers, also referred to as Cleopatra’s Needles.
Moeraki Boulders, New Zealand
These spherical boulders, found on the South Island’s Otago coast, are basically cemented mud and silt, exposed by erosion.
Reed Flute Cave, China
China’s Reed Flute cave is a famous tourist attraction in Guilin. The strange coloring comes from man-made lights.
Haleakala Crater, Hawaii
Haleakala is the dormant volcano on the east side of Maui.
Rhine Falls, Switzerland
The Rhine Falls, near Schaffhausen in Switzerland, is the largest plain waterfall in Europe.
Horsetail Fall, Yosemite National Park, California
Horsetail Fall is a seasonal waterfall that occurs on the east side of the rock formation known as El Capitan. You can see it in the winter and in the early spring. If conditions are just right in February, the water catches the light of the setting sun and turns a fiery orange.
Avenue of the Baobabs, Madagascar
This grove of Baobab trees lies slightly outside the city of Morondava in Madagascar.
The Tunnel of Light, Arizona
The Tunnel of Light is part of Antelope Canyon, pictured earlier.
Devil's Tower, Wyoming
Devil’s Tower in northeastern Wyoming lies in the Black Hills. It is probably most famous for the part it played in Close Encounters of the Third Kind.
The Elbe River, Czech Republic
The Elbe, running through the Czech Republic and Germany, was claimed by the Soviet Union to be the place that Hitler’s ashes were spread.
Tianzi Mountains, China
These towers in the Hunan Province of China are formed of quartzite sandstone pillars.
Lake Baikal, Russia
Lake Baikal is a rift lake in Siberia that is the deepest, most voluminous freshwater lake in the world. It contains about 20% of the world’s unfrozen fresh water.
Half Dome, Yosemite National Park, California
Half Dome is one of the most famous landmarks in Yosemite National Park.
Cathedral Cove, New Zealand
Cathedral Cove is part of Te-Whanganui-A-Hei Marine Reserve on the Coromandel Peninsula of New Zealand. The rock you see here is known as Te Hoho Rock.
Sahara Desert
The Sahara Desert is the world’s hottest and third-largest desert, and it makes up a huge portion of North Africa’s area.
Perito Moreno Glacier, Argentina
Perito Moreno Glacier, in Patagonia, is a famous attraction. Many tourists go trekking on the ice, or visit to watch the calving of the glacier.
The Li River, China
The Li River runs from Guilin to Yangshuo and is famous for its stunning karst views.
Enchanted Well, Chapada Diamantina, Brazil
Chapada Diamantina is a national park that sits on a plateau in Bahia, Brazil.
Nyiragongo Lava Lake, Democratic Republic of Congo
The Nyiragongo volcano is in the Virunga Mountains of the Democratic Republic of Congo. The crater that contained this lava lake fractured in 1977, destroying the lake and killing 70 people.
Raja Ampat Islands, Indonesia
Raja Ampat is a New Guinean Archipelago of over 1,500 islands.
Fly Geyser, Nevada
The Fly Geyser was actually manmade: When settlers drilled a well, they didn't cap it correctly, and this geyser has been formed over time.
Hvitserkur, Iceland
Hvitserkur is the name for this 15-meter basalt sea stack just off the coast of the Vatnsnes Peninsula in Iceland.
Bryce Canyon, Utah
Bryce Canyon is actually not a canyon, but a collection of amphitheaters. The geologic structures seen here are known as hoodoos.
Grand Tetons, Wyoming
The Grand Tetons (French for “The Big Breasts,” because, why not?) are the three largest peaks in the Tetons range, just south of Yellowstone.