What do we actually mean when we talk about 'activity centres' in a housing context?

High-rise apartments could be built at a so called "activity centre" in the south-east suburbs, that's according to draft plans released by the State government. In this edition of The Conversation Hour we explore what activity centres actually are and whether high-density has become a dirty word. Also in this edition, the significant role the game Dungeons and Dragons' is playing in Victoria's autism community, plus some good news for fans of Guns N Roses.