you should make a map with snow covered mountains and a building that has a large set of hallways and rooms, something like the following:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
| | | | | |
| |_ _ _ _ _ _ _ _ _ _ _ _ _| |_ _ _ _ _ _ _ _ _ _ _| |
| _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ |
| | | | | |
| | _ _ _| |_ _ _ _ |_ _ _ _ _ _ _ _ _ _|
|_ _ _ _ _ _ _ | | |
| |
|_ _ _ _ _ _ _ _|
anyways you get the gist... would be simple but a lot of work.