Hoy Island is located in Orkney, Scotland. The highest point in Orkney, Ward Hill, is on Hoy. It represents the second widest archipelago after the Mainland with a surface of 143 square kilometres (55 square miles). The scenic seeshore of Hoy pleases guests travelling to Orkney by ferry. It has extremes of numerous styles: some of the highest seafronts in the UK at St John's Head, which touch 350 metres (1150 feet); the imposing and popular sea stack, the Old Man of Hoy; some of the most northerly surviving natural woodland in the British Isles. The most northerly Martello Towers were constructed to protect the surface over the Napoleonic War, but were never put in battle.