In addition to the Perth Cultural Centre, there are dozens of museums across the city. The Scitech Discovery Centre in is an interactive science museum, with regularly changing exhibitions on a large range of science and technology based subjects. Scitech also conducts live science demonstration shows, and operates the adjacent "Horizon" planetarium. The Western Australian Maritime Museum in Fremantle displays maritime objects from all eras. It houses "Australia II", the yacht that won the 1983 America's Cup, as well as a former Royal Australian Navy submarine. Also in Fremantle is the Army Museum of Western Australia, situated within a historic artillery barracks. The museum consists of several galleries that reflect the Army's involvement in Western Australia and the military service of Western Australians. The museum holds numerous items of significance, including three Victoria Crosses. Aviation history is represented by the Aviation Heritage Museum in Bull Creek, with its significant collection of aircraft, including a Lancaster bomber and a Catalina of the type operated from the Swan River during WWII. There are many heritage sites in Perth's CBD, Fremantle, and other parts of the metropolitan areas. Some of the oldest remaining buildings, dating back to the 1830s, include the Round House in Fremantle, the Old Mill in South Perth, and the Old Court House in the city centre. Registers of important buildings are maintained by the Heritage Council of Western Australia and local governments. A late heritage building is the Perth Mint. Yagan Square connects Northbridge and the Perth CBD, with a 45-metre-high digital tower and the 9-metre statue "Wirin" designed by Noongar artist Tjyllyungoo. Elizabeth Quay is also a notable attraction in Perth, featuring Swan Bells, a panoramic view of Swan River, and the sculpture "Spanda" by artist Christian de Vietri.