The Dynamite Museum is a highly explosive building located in Dimmsdale. It was very quickly destroyed when Timmy bounced through the area on a pogo stick. It's not only Highly Explosive but it could possibly be one whole real Dynamite bundle large enough to allow people in it.
This dynamite shaped building did not last long when Timmy Turner irresponsibly bounced on top of the detonator with Poof, causing the building's top to explode. Later on, Timmy was backtracking his steps when he was trying to find Poof, and he ended up back at the newly re-opened Dynamite Museum. Timmy thought he saw Poof enter and ran in after him, and the detonator went off again while Timmy was inside, blowing him up and destroying the building for good. Its brief existence was only seen during the episode, Bad Heir Day.
The building was shaped like a bundle of dynamite sticks with the TNT lettering, attached to a nearby push down detonator that Timmy landed on top of with his pogo stick, causing the entire building next to him to explode through the roof.