Soos
Valves of the Earth
The Soos National Nature Reserve lies in a shallow basin between Vonšovský Creek and Sooský Creek northeast of Františkovy Lázně. A more than one kilometre long nature trail of wooden walkways has 9 stops and leads through the bed of a dried-up salt lake, where a layer of siliceous sediment several metres thick, known as the diatomite shield, formed from the shells of diatom algae that lived in the lake.
The main phenomena of the reserve are the mineral springs and seeps of gaseous carbon dioxide, called mofettes. The seeps look like small, roughly half a metre wide craters – from some of which gas escapes with a hissing sounding, while in others water and mud (false mud volcanoes) bubbles up. They fill with water during rainfall, and clusters of ice crystals, ice pyramids and columns form around them during freezing temperatures. Shrinkage cracks and yellow and white mineral salt efflorescence cover the bizarre terrain during dry spells.
The reserve is home to a number of protected animals and wetland and halophytic (salt-tolerant) plants that live and grow there. A natural science museum, wildlife shelter and Jurassic Park Pavilion are located in an area near the parking lot.
