This is a review for the park, not the historic site. Kinda strange that there is not a separate entry for the museum.
The park itself is very interesting. It contains the remains of a 19th century garrison cemetery as well as unmarked American burials from the battle of York. There is lots of space for dogs to run around and its quite nice on a spring afternoon.
Also this spot also does concerts and outdoor shows in the summer, so look on Fort York's website to see whats on.