Lough Derravaragh

Lough Derravaragh Loch Dairbhreach
Lough Derravaragh viewed from the summit of Knockeyon hill
Location	County Westmeath
Coordinates	53°38′0″N 7°21′0″W / 53.63333°N 7.35000°W / 53.63333; -7.35000Coordinates: 53°38′0″N 7°21′0″W / 53.63333°N 7.35000°W / 53.63333; -7.35000
Primary inflows	River Inny
Primary outflows	River Inny
Basin countries	Ireland
Max. length	10 km (6.2 mi)
Max. width	4 km (2.5 mi)
Surface area	10.8 km2 (4.2 sq mi)
Max. depth	20 m (66 ft)
Surface elevation	64 m (210 ft)

Lough Derravaragh (Irish: Loch Dairbhreach) is a lough in County Westmeath, Ireland, north of Mullingar between Castlepollard, Crookedwood and Multyfarnham.

Lough Derravaragh sits on the River Inny which flows from Lough Sheelin on its way to the River Shannon. Shaped somewhat like Italy, it is a popular lake for angling and other watersports. The main public area is at Donore near Multyfarnham, where there is a caravan park and shop restaurant open in summer.

There are ringforts to the east of Lough Derravaragh, within the hills of Ranaghan.

Turgesius the Viking, renowned for taking Dublin, also possessed strongholds nearby, southwest of Lough Lene.

Knockeyon, the hill of Saint Eyon, is located on the south-eastern shore of the lough, rising steeply to 215 metres. Halfway up the hill are the ruins of the ancient Saint Cauragh chapel, built and dedicated to Saint Eyon. The chapel was cut out of the natural rock, and is believed to have never possessed a roof. The ruins of Saint Cauragh's Well are adjacent to the chapel.

On the Kiltoom side of the lough mounds of stone can be found, these were part of artificial islands and gave protection to the people who lived in crannógs on these islands. In the 1970s a dug-out canoe from the Stone Age was recovered from the lake by employees of the Tullynally estate.