Cronk ny Merriu (English: Hill of the Dead), located close to Port Grenaugh, is one of the remains of promontory forts in the Isle of Man.

Cronk ny Merriu was previously considered by historians to be a prehistoric burial place due to its large grass-covered bank and name, literally translating to "Hill of the Dead".

Later, a rectangular building of Norse style and layout stood here, part of a system of coastal lookout posts used to protect the coastline and to police beach markets.

[1][2][3] Excavations of Cronk ny Merriu show that there was very little domestic activity, and that the Norse building likely didn't have permanent residency.

[1] It's suggested that the longhouse was primarily a building for those at nearby forts to shelter from harsh weather, rather than a place of defence itself.