Calton Hill (100m high), a former active volcanic site, rises up at the eastern end of Princes Street. The hill is a lovely place for a walk, with its lawns, flowerbeds and copses, and splendid panoramic views, in particular of the new town below. The most breathtaking monument is the National Monument, the unfinished Parthenon. The Nelson Monument is a 32m-high circular tower honouring the victory of Trafalgar.