The Hamilton Waterworks
This dignified building, reminiscent of the style of a Roman aqueduct, houses one of Canada's greatest surviving engineering achievements of the mid-19th century, the Hamilton Waterworks. Built between 1857 and 1859, it was designed by the prominent Canadian engineer, Thomas C. Keefer. Its grand interior, dominated by giant cast-iron doric columns, houses steam engines cast by the nearby Dundas foundry. The pumphouse produced as many as nineteen million litres of water daily until 1910, when increasing demand and improved technology forced its retirement.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.