A friend is doing the RAAM and I was asking him how he was training for the hills, and he gave me this list of the best hills in his opinion in Toronto.
In the city, the best hill I have found is at Bluffer's Park in Scarborough - the bottom of Brimley. If you start right at the bottom in the parking lot and take the hill all the way up to Kingston Rd., it's almost 1500m. There are other steeper hills in the city (though Bluffers is pretty steep for the first half), but not nearly as long . Among the hardest ones are: (i) the hill climbing up to the Redway Rd. Loblaws (off of Millwood) from the sewage treatment plant in the valley; (ii) where Lawrence runs east from Bayview (starts down under the Bayview bridge and run up to the Bridlepath area); and (iii) the hills just west of High Park (Ellis Ave, Ellis Park Rd. and the switchbacks up Harcroft Rd.) If you pick the wrong gearing (especially on the Loblaws hill) these are fall-over-sideways steep - a taste of what you'll get on the switchbacks in France.
I've done the hill that runs up into the Bridlepath area, and it's a good one. Not crazy long, but pretty damn steep.