As well as the museum itself, on this site you'll find the Queen's House, which was designed in 1616 by Inigo Jones but not completed until 1638, and the Royal Observatory, founded in 1675 by Charles II. The museum's Maritime London gallery is a permanent exhibition exploring the importance of London’s maritime heritage and its impact on world trade. Exhibits include wreckage from a Zeppelin shot down over the Thames estuary in 1916, the original model for Nelson’s Column and early 19th-century plans for the Rotherhithe Tunnel. Making Waves is a permanent display demonstrating how tides, currents and waves are formed. Oceans of Discovery, which explores the history of scientific exploration above and beneath the waves, tells the stories of explorers such as Captain Cook, Ernest Shackleton and Jacques Cousteau. Exhibits in the museum's Your Ocean gallery, which is aimed at families and teenagers, examine current issues affecting marine conservation, including global warming, over-fishing and pollution. Environmental concerns inform the construction and running of the gallery itself and visitor feedback on the issues raised is actively sought. The Time Galleries in the Observatory are four new galleries mapping the quest of astrologers, horologists who attempted to pin down the elusive concept of time. Among the astronomical instruments and timepieces dating from the 13th century to the twenty first are telescopes, quadrants, sundials, sandglasses, watches and astrolabes. The Cradle of the Navy: The Royal Hospital School at Greenwich is a permanent display in the Queen’s House on the school’s origins and life at Greenwich, where it occupied the building now used by the museum from 1806 to 1933. London’s only public camera obscura is housed in the Observatory offering a bright reflected image of London’s landmarks including Tower Bridge and St Paul’s Cathedral.