Bob-omb Keep resembles a huge Bob-omb surrounded by castle walls. The top part of the bomb (including the fuse) is cleary visible. The door is huge, circular and black. A huge white (stone) mustache is the only feature on this door. To open the door, you should punch the mustache.
Bob-omb Keep is an explosive deathtrap. Bob-ombs and other explosive enemies abound. Some parts of the floor make explosions when you step on them. Bowser Jr.'s Paint is the most effective way of avoiding the explosions, since it can smother exploding enemies and create safe paths over Exploding Floor. Two Iron Goombas stand guard before Big Bob-omb's chamber.
Bob-omb goes Boom-boom
After Big Bob-omb is defeated, his Mustache will shrink and vanish. 'Stachios will pour out of the hole, along with a Podoboo. The Podoboo will make its way to the Keep's fuse. Paint can be used to slow its progress, but only slightly. Once the fuse is lit, you have five minutes to escape before the Keep explodes.