With a group of people i would have to say the St. John's convent in Toronto
Interesting place but i found the dormitories a little repetitive
Fedge and i happened upon a house in Colborne that had lots of old furniture, televisions, and appliances. We found out later that Atomx had previously explored the house and comparing the pics he had taken to our later ones proved the house to be undisturbed, unlike ourselves
Here is a link to a slide show of pics from the Colborne house
Colborne house And of course i have explored many places by myself and was most impressed with the Red brick farm house near Peterborough.
I compiled the photos ,set them to some music and put them up on youtube
Red brick farmhouseI would suggest pausing it so that the it may load to avoid stoppages