Miniature Sewer Protected Entrance

This is a 28mm miniature locked sewer entrance 2x2 inches. This is going to be the start of stackable sewer tiles. Why not play vertically as well as horizontally? One side most likely will be open to play and the other three sides will contain terrain for future tiles.
To start into the sewer, however, you need an entrance. You don't want just anyone going into the sewers. This has doors that can be opened and closed and two types of sewer grates to cover the hole to the entrance.
Just as a