Benitoite Gem Mine (California State Gem Mine)
The only find of benitoite of gem quality.
Weeki Wachee Springs
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
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)
Impressive rapids or waterfall across Okavango River. Falls are some 900 m wide and 2.5 – 4.5 m high.
Aouk-Kladuk Underground River
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
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
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)
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.