A cryptodepression is a depression in the Earth's surface that is below mean sea level, and which is filled by a lake.[1][2] The term is derived from the Ancient Greek word κρύπτoς ('hidden') and depression.
A cryptodepression is often due to creation of a rift valley or a glacial lake.[3]
Lakes are often long and narrow. Further, the surrounding landscape and the shore of the lake can be very steep.[4]
Simple calculation example: Lago O'Higgins/San Martín Surface elevation 250 m - Maximal depth 836 m = _________________________________ Cryptodepression -586 m