Union Square is an irregular and informal space between Union Street, Paternoster Row and Harris Street.
Union Street began as a steep track from Harris Street to the foreshore where a ferry took passengers across the water to the city.
By 1858 Union Street led to the first Pyrmont Bridge (a privately owned toll bridge) taking pedestrians across to Market Street. Next year the Pyrmont Bridge Company built Pyrmont Bridge Road which veered off Union Street to cross Blackwattle Swamp to Glebe. Union Street became an even busier traffic artery when the old bridge was replaced by the swing bridge.
Union Square was created in 1998 as a by-product, when Union Street and Pyrmont Bridge were closed to vehicles. With open space and level surfaces between steps, it has become the social centre of Pyrmont, the site of the Anzac Day service and Christmas carol services among other events. Its dominant feature is the Pyrmont War Memorial.