English to Czech Science Geology

A dolos (plural dolosse- approximate translation "knuckle bones"; approximate pronunciation "dohl-awe-sah) is a concrete block in a complex geometric shape weighing up to 20 tons, used in great numbers to protect harbour walls from the erosive force of ocean waves. They were developed in East London, a port city in South Africa, in 1963.

http://en.wikipedia.org/wiki/Dolos

díky