Bordering Pennsylvania on the Delaware River is Trenton, which has been New Jersey's capital since 1790. There is plenty here for all visitors, especially those interested in history. Trenton features several museums including the New Jersey State Museum and the Old Barracks Museum. The State House and Mill Hill Historic Districts have preserved many colonial buildings and sites. The William Trent House—considered the city's oldest house—is open for touring and features many period furnishings. Trenton visitors can also enjoy Cadawalder and Washington State Parks, which both host a number of interesting historic features and recreational activities.