SuperHeroHype reports that X-Men 3 will start primary photography at Hatley Castle (Royal Roads University) in Victoria, Canada at the end of July. This local shooting is why I have covered X-Men so extensively.
The report goes on to say, the building will serve as Xavier's School for The Gifted, also know as the X-Mansion. Though the shoot is expected to start in the last week of July, it's believed that 2nd Unit photography could possibly start before that. This a reunion of sorts for cast and crew because the location was also used for X2. Principal photography is expected to last into the middle of August. The cast and crew will then move to Vancouver Film Studios. As we speak, the writers Simon Kinberg and Zak Penn (Who will be at this years Comic-Con, July 14-17) are working around the clock on the script.