Titusville was a city in Florida, proximate to Cape Canaveral, where the Eighth Doctor and Deborah Castle once booked into an hotel to wait out the night prior to their hijack of the Atlantis space shuttle. The Doctor had a couple of fighter pilot pressure suits sent to Titusville for the duo to use onboard Atlantis. (PROSE: Father Time)
Real world location
Though it's possible that a real world location doesn't exist in the same geographic space in the Doctor Who universe, such cases are few and far between. Thus, the map at right is probably a good indicator of the DWU location of Titusville.