"To Althea, from Prison" is a poem written by Richard Lovelace in 1642. The poem is one of Lovelace's best-known works, and its final stanza's first line "Stone walls do not a prison make, Nor iron bars a cage" is often quoted. Lovelace wrote the poem while imprisoned in Gatehouse Prison adjoining Westminster Abbey due to his effort to have the Clergy Act 1640 annulled.