There are a ton of resources available that show the end result of tile-based games. Fans, hobbyists etc, painstakingly capture entire dungeons, shops, towns and world maps etc. from their favorite games. The TileMapper project is a tool created using Unity which allows you to easily extract the unique tiles from a tile map (for educational purposes of course). It has a variety of features to make this process easy and even includes a feature to help you recreate the map using the newly captured tiles.