Through May 21, the Art Gallery of Hamilton is presenting Edward Burtynsky’s Witness. The artist offered 76 images to the museum as a gift, and this exhibition celebrates the donation. Burtynsky’s impressive large-format images highlight the environmental impact of global manufacturing, the oil industry, marble quarries, salt pans and more. An exhibition preview is available here. The museum offers free exhibition tours at 1 p.m. on Wednesdays, Saturdays and Sundays.