Google Maps has a feature to display 45 degree imagery and at the same time to allow the user to rotate the map in 90 degree increments (there is a button for that).
However, the trouble is that this feature only shows up sometimes:
It also happens to disable the display of tile overlays when it’s enabled, which may not be desirable.
Fortunately, it’s easy to disable this feature and restore tile overlays. Simply pass the appropriate flags to the map constructor:
map = new google.maps.Map(document.getElementById("my_map"), {
zoom: 10,
center: center_coord,
mapTypeId: map_type,
rotateControl: false, // disable 45 degree imagery and map rotation
tilt: 0 // in addition, set view tilt to 0 degrees -
// just to be sure
});