Public domain maps

http://www.openstreetmap.org/
OpenStreetMap is a free editable map of the whole world. It is made by
people like you.

OpenStreetMap allows you to view, edit and use geographical data in a
collaborative way from anywhere on Earth.

OpenStreetMap's hosting is kindly supported by the UCL VR Centre
(http://www.vr.ucl.ac.uk/) and bytemark. http://www.bytemark.co.uk/