Shannon Pot is a pool in the karst landscape in the townland of Derrylahan near Cuilcagh Mountain in County Cavan, Ireland. An aquifer-fed naturally fluctuating pool, it is the traditional source of the River Shannon. It has connections, through the Shannon Cave system, to other pools, notably two in County Fermanagh. The pool itself is about 16 metres (52 ft) wide, and has been dived to 14.6 m (48 ft) depth. Settlements near the Shannon Pot include Dowra, Blacklion and Glangevlin.