There’s more to Google Earth than finding a satellite view of your house — which is cool enough — or even seeing the land where your characters walk. You can also find the altitude of any particular spot just by rolling the pointer over it or use the ruler to measure distances from point to point. Optional links (which show as dots on the photo) take you to Wiki links about famous sites and to photos of many locations (even not-so-famous ones). Important buildings and monuments, and some entire downtown areas, are modeled in 3D (trying flying around downtown San Francisco).
Yes, it does take a fast internet link and a computer with a hi-powered graphics processor (I recommend a Mac, but then I always recommend a Mac <g>), but once you have the software, available free on the Google Earth site linked above, the entire world literally opens up to you.
If you already have Google Earth (or once you get it), you can check out the area where Immortal Warrior is set. Cut and past the following latitude/longitude:
55°24’56.63″N x 1°42’21.88″W
Just remember, you’re visiting about 900 years late.