The highlight here is a tour of the newly restored World War II submarine HMS Alliance from the cramped quarters to the engine room. Here you can learn about submarine history and the rigors of life below the waves. There are three actual subs spread around the large site, including Holland 1, the first Royal Navy sub built in 1901. From Portsmouth Harbour, take the ferry to Gosport and walk along Millennium Promenade past the huge sundial clock. From April to October, an hourly waterbus runs from the Historic Dockyard.