Events take place in a wide range of locations. Some of these are relatively natural environments such as moorlands for the Three Peaks Run or the sea for the Clipper Yacht Race. These locations may have temporary facilities such as mobile toilets or catering but the location can be returned to its natural state relatively quickly. Others may make use of parkland or other tightly managed open environments. The use of these can be controversial, such as the use of Greenwich Park for equestrian events in the 2012 London Olympics. Some take place in multi-purpose locations such as schools or churches. Many, however, take place in purpose-built venues designed to house particular events, such as theatres, or to house a range of events, such as the National Exhibition Centre in Birmingham or the O2 Arena in London. These types of arena have a long history. Stonehenge, dating back 3500 years, could be seen as an early venue for (quasi) religious events. The theatre at Epidaurus dates to c.350 BC and the Coliseum in Rome dates to AD 79-82. These venues all have interactions with the environment – the environment influences their location, their design and their function. In turn they have impacts on the local, regional and global environment. These interactions form the basis of this chapter.