Khoun Xe Cave (Xe Ban Fai Cave)

Inhabitant of Khoun Xe Cave - Heteropoda maxima, the largest spider in the world

Giant and unique cave, 13.6 km long. Upstream entrance is a giant sinkhole. The cave contains the largest known rimstone pools (gour pools) in the world – up to 60 m wide. Xe Bang Fai river flows through the cave for a 7 km long stretch and is one of the most powerful cave rivers in the world. Width of this underground river – 56 – 100 m. The ceiling of the cave is up to 120 m high, width is up to 200 m. The cave contains the largest known cave pearls in the world – 32 cm in diameter and even larger weird formations called Alien Eggs. Stalagmites over 20 m tall. More than 130 species of fish live in caves, some several meters long. Giant, very fast cave spiders including the giant huntsman spider.

Pierre Saint-Martin Cave

Powerful spotlights try to illuminate the Salle de la Verna, France

Part of the cave is located also in Spain. A very long cave system, length of explored passages – 86,620 m. Up to 1,408 m deep (19th in the world). 7 entrances on the French side, 4 – on the Spanish side. One of the entrances starts with a very impressive 320 m deep abyss. Contains enormous underground voids including Salle de la Verna (the 22nd largest in the world) and Salle de l’Eclipse (the 19th largest in the world). In the Wind tunnel, there is constant wind with a speed of 11 m/s.

Wakulla Cave System

Big Dismal sinkhole, Florida

The longest mapped underwater cave system in the United States where one entrance is at Wakulla Springs. The total length of the explored passages is 72,171 m.

Sally Ward Spring

Sally Ward Spring, Florida

A spring with a magnificent underwater cave system below it. The length of explored passages is 2,195 m.

St Marks River Rise

St. Marks Rise, Florida

The last rise of St Marks River above the ground before its fall in the Gulf of Mexico. This river several times disappears underground and then emerges again.

Indian Spring, Wakulla

Indian Spring, Florida

A comparatively weak spring that is discharging 17 l of water per second. Dive in this spring leads into a 3,626 m long cave with a strong current.

Cherokee Sink

Cherokee Sink, Florida

A rounded jade green pool, 90 by 50 m large, surrounded by 0.5 – 9 m high cliffs. It has steep sides under the water as well and is up to 24.4 m deep. The sinkhole was formed by a collapse of the cave chamber and most likely was considerably deeper in the past.

Yogoluk Sinkhole

Up to 240 m deep and 180 m wide sinkhole with vertical walls, formed over underground river.

Mainina Ponor

In this ponor disappears water from the largest freshwater lake of Timor-Leste – the whole Irasiquero River flows in it. Water continues to flow underground and discharges into the sea. Sacred place. Endemic fish Craterocephalus laisapi has been discovered in this short stream.