What a place. If you are new to Pittsburgh, or just visiting, a stop at Bar 11 is a must. As other people have noted... the atmosphere is just totally hilarious. Depending on what time of year you go, there may be sand on the floor, a "snow" machine, or if you're (un?)lucky it might just be the Summer Solstice rain party. If you do end up at a rain party, be sure to take a hefty dose of Emergen-C before attending and prepare to have a cold for at least the next four to six weeks. Another favorite for me is the hanging drum set - the bartender/maybe owner will usually play along with whatever early 2000s song is blasting at the time. There is also a beer vending machine where you can get a $1 mystery beer - at best this will be Genese light, so brace yourself.
This is a dive bar on steroids. Maybe not steroids. Maybe shrooms. I don't know. Either way, prepare for an experience unlike any other!