Sammer's Proving Grounds
From the Super Mario Wiki, the Mario encyclopedia
Sammer's Proving Grounds is the location of rounds 51-75 in the Duel of 100 of Super Paper Mario. It is characterized by its brownish orange buildings. It is technically Chapter 6-3, but it is not visited in the main story, as the Sammer's Kingdom was destroyed by the Void in Chapter 6-2.
Duel of 100