The Pit is the main bar in the UBC Student Union building. It has the distinction of being named by David Suzuki, while he was working as a professor at UBC back in the 60's. Apparently, he called it "the Pit" because of the bar's proposed location in the bowels of the student union building.
As an interesting aside, when the AMS built a bistro across from the Pit a few years ago, they decided to name it the Pendulum. Personally, having eating establishments named the Pit and the Pendulum in my student union building doesn't exactly strike that warm fuzzy chord in my heart.