Richmond Castle = Riche Mount or strong hill

 "Up above a castle! Down below a stream.
Up above a ruin! Down blown a dream.
Man made the castle, rude, forbidden, bare.
God made the river swift, eternal, fair."
\Mr. Wise 1830

Rounded arches were built before 1100.

The "voussoirs" (specially shaped stones in the arch) were put up using a wooden frame.

Richmond Castle is associated with battles for 1,000 years-the Battle of Hastings to the Battle of Britain.  General Robert Baden Powell, the founder of the Boy Scouts, was commander here from 1908-1910.