The Royal Ontario Museum is located at:
100 Queen's Park
Toronto, Ontario
M5S 2C6
416-586-8000 
www.rom.on.ca
The ROM opened in 1912, and has been expanding since. These days it gets about 750kilovisits per year. Collections comprise over 6 million objects (4,900,000 science specimens; 1,100,000 art and archaeology artifacts). Approximately 67,000 items are added each year.

There is always something cool there, and the permanent exhibits, on Egypt, and dinosaurs, and the famous bat cave, (my favorites as a kid) are still there.