With two layers of castle walls in a hexagonal shape with unequal sides, the Tower of London is one of the oldest buildings in London. It was built in 1078 by England’s King William I, as a citadel centered on the White Tower and intended as a defense against revolt by the people of London. It was remodeled in various ways over the following 500 years, resulting in its current appearance. Although it housed the royal family until the reign of King James I (1603 to 1625), it was later used as a jail for political prisoners, serving as the scene of numerous historical tragedies including the imprisonment of Queen Elizabeth I and a number of executions. This papercraft model represents the White Tower, one of the 13 towers found within the Tower of London.