My son is a big fan of maps. He's got a terrific sense of direction and knows exactly where the toystore is in any mall we frequent. When we eat at a restaurant, I've always got a pack of crayons ready to draw him a map or set of train tracks on the back of the paper placemat (because the restaurants we like are classy like that). Hubby and I have drawn approximately 100 maps, we estimate. Each getting soggy and wet at the end of each meal.
I recently found a scrap of tarpaulin (sp?) left over from our daughter's birthday party. We used it as the backdrop of her photo booth (a present from godparents). The tarp is really durable, we used it underneath a picnic blanket to keep our butts dry (but it was too slippery), underneath finger painting projects and it's final incarnation (or so I thought) was to cover the unsightly corkboard in my classroom. The scrap was from the bottom end that was longer than the board.
So I took my handy permanent markers and drew him a map. The houses have numbers or letters (he's learning them now) and there is a gas station, bakery, bookshop, zoo, hospital, church and swimming pool in the neighborhood too. And a river runs through the town.
I brought it home and he ran to the toy cabinet to find his cars. There was no talking to him for the rest of the afternoon.