Buffy Summers and the Scooby Gang attended Sunnydale High, which was famous for it's slightly creepy swim team and mascot the razor-back. In addition to its perchance for getting its principals eaten, its library was situated on the Hellmouth and basically attracted evil constantly. Any number of demons, if performing the proper incantations, could rise out of the Hellmouth at any time. Other than the Hellmouth, the school was a favorite target for evil because evil seemed to know the Slayer would be attending every day of the week. The school is currently not in use since Giles blew it up in Graduation Part 2.