1.) A small hole in the side of a hill
2.) A sea cave
3.) What's behind the doors?
4.) A hole in the ground
5.) Old mine shaft?
6.) Underneath the tower is the entrance to the dungeon.
7.) At least three ways into the dungeon--or are there three separate dungeons?
8.) Even mega dungeons have separate entrances for servants.
9.) Another sea cave.
10.) The guardian of the entrance
11.) Hopefully you can pick the lock--I don't think this door can be broken down.
12.) Creepy entrance
13.) A jungle entrance
15.) This looks like something that Bran Mak Morn would take on. Not me though.
16.) This doesn't look safe.
17.) The way is shut. It was made by those who were dead, and the dead keep it. The way is shut.
18.) Sometimes even the wizard is helpless.
19.) Ice cave
20.) Secret fortress for the super villain?
And a bonus. I hope there aren't any alligators down there.