Bob-omb Battlefield

From Mariopedia

Bob-omb battlefield is the first mario 64 world Mario visits.Mario does not need any power stars to enter this world. It appears as a war-zone with bob-ombs fighting bob-omb buddies.There is a summit where king Bob-omb is doing something. Cannons are spread all around the level which Mario can go into(most of them). This is the only level that has a boss fight that is fought twice.

[edit] oddities

This is a level that clearly has a gravitational force, there are some floating islands that are defying gravity like whomp's fortress.