Lough Key
| Lough Key | |
|---|---|
| Loch Cé (Irish) | |
Lough Key and Castle Island | |
| Location | County Roscommon |
| Coordinates | 54°0′N 8°15′W / 54.000°N 8.250°W |
| Basin countries | Ireland |
| Max. length | 5 kilometres (3.1 mi) |
| Max. width | 3 kilometres (1.9 mi) |
| Surface area | 843.7 ha (2,085 acres) |
| Average depth | 5.1 m (17 ft) |
| Max. depth | 21.8 m (72 ft) |
| Water volume | 43 hm3 (35,000 acre⋅ft) |
| Islands | 32 (incl. Castle Island, Stag Island, Bullock Island, and Drumman's Island) |
Lough Key (Irish: Loch Cé) is a lake in Ireland. It is in the northwest of County Roscommon, northeast of the town of Boyle. The lough is believed to be named after a mythical figure named Cé.