More than 50 sites will participate in this year's Doors Open Hamilton on the weekend of May 4. Buildings that are rarely open to the public - such as Auchmar, the Dundas Wastewater Treatment Plant, the John Weir Foote Armoury and the Westinghouse HQ - will be among the featured sites for the annual free event. For further information, go to www.hamilton.ca/DoorsOpen.