Weeki Wachee Springs

Weeki Wachee stream below the springs, Florida

Large spring, coming from a cave. The explored depth of cave is 124 m and thus it is the deepest freshwater filled cave in the United States. Explored length of passages – 7,260 m. Unique underwater theater – mermaid show – operates here since 1947.

Dura-Europos house church

Remnants of Dura-Europos house church, Syria

One of the oldest Christian house churches – a family house that was converted into church sometimes around 233 – 256 AD. Possibly the oldest church in the world. It is adorned with frescoes – possibly the oldest Christian paintings.

Popa Falls (Popa Rapids)

Popa Falls, Namibia

Impressive rapids or waterfall across Okavango River. Falls are some 900 m wide and 2.5 – 4.5 m high.

Aouk-Kladuk Underground River

Kladuk River in the Kladuk Abyss

World’s most powerful underground river. Aouk-Kladuk Underground River is some 1.5 kilometres long. The stream has a volume of 130 – 180 cubic meters.

Keek sinkhole

Keek Sinkhole, Aouk Underground River

One of the tiankengs of Aouk Underground River. Keek sinkhole is bell-shaped hollow that is some 160-180 m deep, its volume is 1.4 million cubic meters.

Hafasu Tiankeng

One of the tiankengs of Aouk Underground River. Hafasu Tiankeng is some 100 m deep, with a volume of 12 – 15 million cubic meters.

Kuom Tiankeng

One of the tiankengs of Aouk Underground River. Kuom Tiankeng is some 100 – 160 m deep, with a volume of 15 – 20 million cubic meters.

Aouk Underground River

Waykut - entrance in the Aouk Underground River. Note the speleologist in the center

Amazing system of more than 6 km long underground passages with one of the most powerful underground rivers in the world. System has three tiankengs.

Jog Falls (Gersoppa Falls)

Jog Falls, India

The most impressive waterfall in India – Sharavati River here falls 253 meters. Width of the waterfall reaches 580 m during the monsoons – then it is one of the world’s most impressive waterfalls.