On the corner of Collins and King Street stood Robb's Buildings, named for the owner, railway builder John Robb, a grand classical styled 5-storey Victorian office building designed by Thomas Watts and Sons in 1885, and one of the largest in the city at the time. The site of the whole Rialto development ran between Flinders Lane and Collins Street, and was occupied by several buildings including numerous small warehouses on Flinders Lane, with lanes between including and Winfield Square and Robbs Lane. The original Rialto Building was retained as part of the development. It was also the location of Melbourne's first Tower running event. The Rialto featured Melbourne's first skyscraper public observation deck, which operated between 1994 and 31 December 2009.
It was the tallest office building in the Southern Hemisphere when it was constructed. Rialto (often The Rialto, or Rialto Towers) is a skyscraper located at 525 Collins Street, in the western side of the central business district of Melbourne, Victoria, Australia.
Rialto as viewed from the base of the towers, in May 2017