The map of Colinstown is located on the home screen. The majority of its locations are the buildings you complete game levels in. There are scrolls with building names, and padlock icons for locked buildings.
Unlock these with Coins once you have reached the required Experience Level.
If you are just a level short of unlocking a building, you can do so by spending Crystals instead.
All told, the elements you can find on the map are: