‘The cave you fear to enter holds the treasure you seek’. Caves are natural secretive chambers formed due to the gradual erosion of natural minerals and rocks.

These cavities in the sea, mountain, or ocean hold beauty and serenity which has awed explorers and adventures of every century. Caves in the heart of a mountain, dry caves are the mines of unique minerals etched on the wall.

Caves in the hollow of the ocean or sea, underwater caves, are an incredible location to witness the rare species of fishes, flora, and fauna.

In this article, I will list ten longest caves of the world that would craft a room into your ‘bucket list’.

1. Mammoth Cave

Longest Caves of the World
Source: kknews

History of humankind with mammoth cave dates 6000 years back. The longest cave is an international biosphere reserve and world heritage site situated in the Kentucky State of U.S.A.

It is stretched over a length of 652km, which is twice the length of the second largest cave system located in Mexico.

2. Sistema Sac Actun and Sistema Dos Ojas

Longest Caves of the World
Source: Weirdworm

Sistema Sac Actun and Sistema Dos Ojas literally from Spanish translate into English as ‘white cave system’ and ‘two eyes’. This underground cave system tracks along the Caribbean coast of the Yucatán Peninsula.

Actun measures the length of 230.8 kilometers and connection to Sistema Dos Ojas raises it to 319 km, the longest cave in Mexico and the second longest worldwide.

3. Jewel Cave

Source: Taringa

Located in the west of the town of Custer in South Dakota’s the Black Hills, the third-longest cave system is a mapped and surveyed passageway of 180 miles and is subject to human curiosity.

Its splendor is revealed through fragile formations and glimpses of brilliant color. Its maze of passages lure explorers, and its scientific wealth remains a mystery.

4. Sistema Ox Bel Ha

Longest Caves of the World
Source: vietkings

Sistema Ox Bel Ha is Mayan expression for “three paths of water” situated in Quintana Roo, Mexico. Sistema Ox Bel Ha is the longest explored underwater cave system in the world and holds the fourth position in my list.

It is stretched over the area of 269.8 kilometers.

5. Optymistychana Cave

Source: Susidy

Optymistychana Cave is a Ukrainian expression of ‘optimistic’ is a gypsum cave located near the Ukrainian village of Korolivka.

The cave stands fifth regarding the longest in the world but covers 230 km of the mapped passageway and is the longest cave in Eurasia. Cave encompasses a dense network, making Optymistychna known as a “maze cave”.

6. Wind Cave

Longest Caves of the World
Source: Thinglink

The relic island of intact prairie secretes one of the longest and most complex caves in the world, wind caves.

It is prominent for its display of calcite formation known as box work and frostwork along with being one of the densest maze cave systems; it is the sixth-longest cave system covering the stretch of 226.06 km of the explored passageway.

7. Lechuguilla Cave

Source: Simpleandinteresting

The seventh most explored cave system, Lechugilla is notable for its depth and unusual geology. The cave is named after, a species of plant found near its cavity ‘agave lechuguilla’.

The present measure of the cave is 156.5km and is yet to be measured and explored.

8. Clearwater Cave

Longest Caves of the World
Source: Borneotalk

Clearwater is the largest interconnected cave system situated in the Gunung Mulu National Park, Sarawak, Malaysia. Clearwater lies below the western margin between the Melinau Gorge and Cave of the Winds.

The 8th longest cave system covers the area of 215.3 km.

9. Fisher Ridge Cave

Source: Flickr

Fisher Ridge is situated close to the largest cave system, mammoth cave system, and includes the stretch of land measuring 200.5 km.

The credit for the discovery goes to Michigan cavers associated with the Detroit Urban Grotto of the National Speleological Society.

10. Holloch Cave

Longest Caves of the World
Source: Freizeit

Holloch is the second largest cave system in Europe covering almost 200.4 km in Muotathal municipality in Switzerland.

A leading pioneer, Alfred Bögli was the face of the most extensive exploration of Holloch which was earlier initiated by Alois Ulrich in 1875.

Caves are the beginning, full of curiosity, adventure, and lust for more. All art, from the paintings on the walls of cave dwellers to art, created today, is autobiographical because it comes from the secret place in the soul where imagination resides.