Hattiesburg Pocket Museum
Tucked away somewhere in downtown Hattiesburg lies the Hattiesburg Pocket Museum, "Mississippi's Smallest Museum". It remains open 24/7 thanks to the special exhibits being little more than a literal hole in the wall, displayed behind protective glass. A few presumably permanent exhibits lurk outside, sometimes transfixed (glue helps!), and sometimes (literally) hanging from the pipes up above.
Don't ask where it is. Part of the fun lies in finding it. But, you can probably figure out the location if you orient yourself according to that handsome building there on the right: downtown Hattiesburg has but a few alleys.