One of the ongoing tourist attractions of the bridge has been the south-east pylon, which is accessed via the pedestrian walkway across the bridge, and then a climb to the top of the pylon of about 200 steps. Not long after the bridge's opening, commencing in 1934, Archer Whitford first converted this pylon into a tourist destination. He installed a number of attractions, including a café, a camera obscura, an Aboriginal museum, a "Mother's Nook" where visitors could write letters, and a "pashometer". The main attraction was the viewing platform, where "charming attendants" assisted visitors to use the telescopes available, and a copper cladding (still present) over the granite guard rails identified the suburbs and landmarks of Sydney at the time. The outbreak of World War II in 1939 saw tourist activities on the bridge cease, as the military took over the four pylons and modified them to include parapets and anti-aircraft guns. In 1948, Yvonne Rentoul opened the "All Australian Exhibition" in the pylon. This contained dioramas, and displays about Australian perspectives on subjects such as farming, sport, transport, mining, and the armed forces. An orientation table was installed at the viewing platform, along with a wall guide and binoculars. The owner kept several white cats in a rooftop cattery, which also served as an attraction, and there was a souvenir shop and postal outlet. Rentoul's lease expired in 1971, and the pylon and its lookout remained closed to the public for over a decade. The pylon was reopened in 1982, with a new exhibition celebrating the bridge's 50th anniversary. In 1987 a "Bicentennial Exhibition" was opened to mark the 200th anniversary of European settlement in Australia in 1988. The pylon was closed from April to November 2000 for the Roads & Traffic Authority and BridgeClimb to create a new exhibition called "Proud Arch". The exhibition focussed on Bradfield, and included a glass direction finder on the observation level, and various important heritage items. The pylon again closed for four weeks in 2003 for the installation of an exhibit called "Dangerous Works", highlighting the dangerous conditions experienced by the original construction workers on the bridge, and two stained glass feature windows in memory of the workers. In the 1950s and 1960s, there were occasional newspaper reports of climbers who had made illegal arch traversals of the bridge by night. In 1973 Philippe Petit walked across a wire between the two pylons at the southern end of the Sydney Harbour Bridge.