21. The featured activity is an hour-long boat ride on the subterranean river in a 17-person boat equipped with lighting. 22. A Karst topography consisting of caves, sinkholes, and subterranean river channels resulted but were later filled with more limestone. 23. We took a leisurely inner-tube ride down a lazy river, then jumped into natural wells fed by subterranean rivers . 24. It has a subterranean river long, with an average depth of and maximal depth of, and a daily discharge of. 25. Sinking Creek was so named because it is a subterranean river for some of its length, disappearing underground before surfacing again. 26. Some fish ( popularly known as cavefish ) and other troglobite organisms are adapted to life in subterranean rivers and lakes. 27. The building itself, was built over a 900 year old sacred well drawing from the River Fleet, a subterranean river underneath London. 28. After taking a wrong turn, they run out of water and Axel almost dies, but Hans taps into a neighbouring subterranean river . 29. Most tourists come to Puerto Princesa to visit the Puerto Princesa Subterranean River National Park located 50 km north of the city. 30. Losing streams are also common in regions of karst topography where the streamwater may be completely cavern system, becoming a subterranean river .
