Ravensnook Castle, an old baronial fortalice in Penicuik parish, Edinburghshire, on the right bank of the North Esk, opposite Penicuik House. It belonged to Oliver Sinclair, commander-in-chief of the forces in the time of James V., and it is now reduced to fragmentary ruins.

(F.H. Groome, Ordnance Gazetteer of Scotland (1882-4); © 2004 Gazetteer for Scotland)