Comic Con

Also, if you are there around July 1, there is the nearby National Capital Airshow in Ottawa and there are many museums in Ottawa, including Science and Technology (trains), Natural History, Aviation, War Museum, Mint/Currency, Art plus a cultural museum across the river in Hull, Quebec.

There is a decommissioned government underground bunker from the 1950's/60's in Carp, Ontario which is just west of Ottawa. It is now a museum and there are daily tours in the summer. It was designed to support hundreds of government ministers and bureaucrats. Highlights: the blast door, prime minister's bedroom, multiple levels, equipment room, tv broadcast facility.

You forgot Bletchley Park in the UK! This is the epitome of computer geekiness - the place where the enigma code was broken the father of modern computing, Alan Turing!