Best of · underground

The 27 Most Incredible Caves and Karst Landscapes

27 places in the atlas

The world underground and the strange stone country it makes above: chambers and underground rivers, limestone towers and hidden valleys. These are the atlas’s caves and karst landscapes.

Benagil Sea Cave, Benagil, Algarve, southern Portugal

Benagil Sea Cave

Benagil, Algarve, southern Portugal

A domed sea cave on the Algarve coast whose vaulted limestone roof is pierced by a great circular skylight — an 'oculus' that pours a column of sunlight onto a hidden beach reachable only from the water.

Eisriesenwelt, Werfen, Salzburg, Austria

Eisriesenwelt

Werfen, Salzburg, Austria

The largest ice cave on Earth — 42 kilometres of limestone passage in an Alpine cliff, its entrance chambers filled with towering formations of natural ice.

Gunung Mulu, Sarawak, Borneo, Malaysia

Gunung Mulu

Sarawak, Borneo, Malaysia

A Bornean rainforest hiding some of the world's greatest caves — including the largest cave chamber on Earth — plus razor-sharp limestone pinnacles rising from the jungle canopy.

Hạ Long Bay, Gulf of Tonkin, northeastern Vietnam

Hạ Long Bay

Gulf of Tonkin, northeastern Vietnam

A jade-green sea studded with nearly 2,000 limestone karst islands and pillars rising sheer from the water — caves, hidden lagoons, and floating villages in one of the world's most beautiful seascapes.

Marble Caves, General Carrera Lake, Aysén, Chile

Marble Caves

General Carrera Lake, Aysén, Chile

Swirling caverns of polished marble at the water's edge of a remote Patagonian lake — their blue-and-white walls glowing turquoise with the reflected light of the glacier-fed water.

Phong Nha-Kẻ Bàng, Quảng Bình Province, Vietnam

Phong Nha-Kẻ Bàng

Quảng Bình Province, Vietnam

An ancient limestone landscape riddled with the world's greatest cave systems — including Sơn Đoòng, the largest cave passage on Earth, big enough to hold its own jungle, river, and clouds.

Puerto Princesa Subterranean River, Puerto Princesa, Palawan, Philippines

Puerto Princesa Subterranean River

Puerto Princesa, Palawan, Philippines

One of the world's longest navigable underground rivers, winding 8.2 km through a vast limestone cave system beneath a karst mountain range before emptying directly into the West Philippine Sea.

The Yucatán Cenotes, Yucatán Peninsula, Mexico

The Yucatán Cenotes

Yucatán Peninsula, Mexico

Thousands of natural sinkholes opening into a hidden world of crystal-clear groundwater and flooded caves beneath the Yucatán — the peninsula's only natural fresh water and among the most beautiful swimming holes on Earth.

Tsingy de Bemaraha, Melaky, western Madagascar

Tsingy de Bemaraha

Melaky, western Madagascar

A vast 'forest of stone' — a labyrinth of razor-sharp limestone pinnacles rising in grey blades from the Madagascar wilderness, hiding canyons, caves, and creatures found nowhere else.

Blue Cave of Biševo, Biševo island, off Vis, Dalmatia, Croatia

Blue Cave of Biševo

Biševo island, off Vis, Dalmatia, Croatia

A sea cave on the tiny island of Biševo that fills with an unearthly blue light around midday, when sunlight enters through a submerged opening and glows up through the water onto the cavern's walls.

Callao Cave, Peñablanca, Cagayan, Northern Luzon

Callao Cave

Peñablanca, Cagayan, Northern Luzon

A vast limestone cave of seven great chambers lit by natural skylights — and the site where the ancient human species Homo luzonensis was discovered, deep in the karst of the Cagayan Valley.

Guilin & the Li River Karst, Guangxi, southern China

Guilin & the Li River Karst

Guangxi, southern China

The landscape of Chinese scroll paintings brought to life — thousands of rounded limestone peaks rising from green plains and the winding Li River, mirrored in still water beneath drifting mist.

Hpa-An Karst, Kayin State, southeastern Myanmar

Hpa-An Karst

Kayin State, southeastern Myanmar

A landscape of sheer limestone karst mountains rising straight from emerald rice paddies in southeastern Myanmar, riddled with vast caves full of Buddha images and roosting bats.

Kong Lor Cave, Khammouane Province, central Laos

Kong Lor Cave

Khammouane Province, central Laos

A river cave that tunnels for over seven kilometres straight through a limestone mountain — navigated by longtail boat through pitch darkness, from one green valley to another.

Los Haitises National Park, Samaná Bay, Dominican Republic

Los Haitises

Samaná Bay, Hato Mayor, Monte Plata and Samaná provinces, Dominican Republic

A limestone plateau eaten into hundreds of conical hills of almost identical height — and where it meets Samaná Bay, the hilltops continue offshore as forested islets standing in the water.

Mammoth Cave, Kentucky, USA

Mammoth Cave

Kentucky, USA

The longest cave system known on Earth — over 685 kilometres of mapped passages winding beneath the Kentucky hills, with new miles still being discovered.

Masungi Georeserve, Baras, Rizal, Philippines

Masungi Georeserve

Baras, Rizal, Philippines

A dramatic limestone karst landscape barely 90 minutes from Manila, reborn as a conservation project — jagged rock formations, rope courses, and hanging viewpoints woven through a rainforest being restored tree by tree.

Melissani Cave, Karavomylos, Kefalonia, Ionian Islands, Greece

Melissani Cave

Karavomylos, Kefalonia, Ionian Islands, Greece

An underground lake on the Ionian island of Kefalonia, roofed by a collapsed cavern that lets a shaft of midday sun ignite the brackish water in an unearthly electric blue.

Phang Nga Bay, Andaman Sea, southern Thailand

Phang Nga Bay

Andaman Sea, southern Thailand

A calm emerald bay between Phuket and Krabi studded with sheer limestone karst islands, sea caves, and hidden tidal lagoons reached by paddling through the rock.

Prometheus Cave, Imereti, near Kutaisi, western Georgia

Prometheus Cave

Imereti, near Kutaisi, western Georgia

A vast karst cave near Kutaisi, its huge chambers hung with stalactites and curtains of stone, explored on lit walkways and, in part, by boat along an underground river.

Sagada, Sagada, Mountain Province, Cordillera, Philippines

Sagada

Sagada, Mountain Province, Cordillera, Philippines

A cool, pine-clad limestone highland in the heart of the Cordillera, where caves riddle the karst, waterfalls drop into rice terraces, and dawn breaks over a sea of clouds at Kiltepan.

Scărișoara Ice Cave, Apuseni Mountains, western Romania

Scărișoara Ice Cave

Apuseni Mountains, western Romania

A cave in Romania's Apuseni Mountains that holds one of the largest underground glaciers in the world — a block of ancient ice thousands of years old, deep beneath the forest.

The Blue Grotto, Isle of Capri, Campania, Italy

The Blue Grotto

Isle of Capri, Campania, Italy

A sea cave on the island of Capri where sunlight passing through an underwater opening fills the whole cavern with an unearthly, glowing electric-blue light.

The Burren, County Clare, Ireland

The Burren

County Clare, Ireland

A silver-grey moonscape of bare limestone pavement in County Clare — one of Europe's finest karst landscapes, where Arctic, alpine and Mediterranean wildflowers bloom together in the cracks of the naked rock.

Vang Vieng, Vientiane Province, central Laos

Vang Vieng

Vientiane Province, central Laos

A dramatic landscape of sheer limestone karst peaks rising above the Nam Song river and green rice fields, riddled with caves and blue lagoons, in the hills north of Vientiane.

Stylised illustration of Viñales Valley

Viñales Valley

Sierra de los Órganos, Pinar del Río Province, western Cuba

Round-topped limestone towers standing up to 300 metres out of flat red tobacco fields in western Cuba — the same tower-karst process that built Ha Long Bay, on an island, and still farmed by hand.