Wikipedia
Drowning-pit
A 'Drowning-pit', 'Drowning pool' or 'Murder-hole' was a pit or well dug for the purpose of specifically executing females under Scottish feudal laws. Rivers, lochans, etc. were used if conveniently situated near to the Moot hill where the baronial court dempster would announce the death penalty. The term 'Fossa' was also used as in 'furca and fossa', the fossa being a ditch filled with water.