The modern-day Tower Bridge over the Thames River is clean and sanitary, but it wasn't always like that. In the nineteenth and early twentieth centuries, the high-level open-air walkways between the towers gained an unsavoury reputation as a hangout for prostitutes. As the walkways were only accessible by steep stairs, they were seldom used by regular pedestrians. Given that the majority of people using the upper level were up to no good, the City of London decided to close the walkways in 1910. However, in 1982 they were reopened as part of the Tower Bridge Exhibition, one more giving law-abiding citizens the chance to enjoy the views from the top of the bridge.