Mysterious tunnels or "secret passages" are a common element of the local folklore tradition in Europe. Such tunnels are said to physically link prominent places such as country houses, castles, churches, ancient monuments and other, often medieval, buildings. Legends about the existence of secret tunnels usually involve improbably long subterranean passages, sometimes running under major obstacles such as rivers and lakes to reach their destinations. Religious buildings, monks and the landed gentry are particularly common elements in many tunnel stories.