This is the area behind the fence in Strongbadia. It was first seen in the "Strong Bad Is In Jail Cartoon", but was actually first seen occupied by the 'shark-holding bear' trap and 'takin' a leak' Coach Z.
Strong Bad used this area to store all of his stolen goods. Such goods included (but are not limited to):
The King of Town's Crown
The Poopsmith
Cookie Jar Trivia Time
Senor Cardgage's Bag-o-Mysterious Contents
Strong Sad tipped Homestar and Coach Z off about this otherwise hidden location. Thank goodness. If he didn't, then we might end up with a rich Strong Bad, which would lead to a pampered and lazy Strong Bad. We don't want that, do we.