The Mather Lather has certainly earned its place as a revered tradition in the Mather House legacy. The bash, which draws more than 1,000 students from across all of Harvard’s Houses, typically goes until the wee hours of the morning.

But before the party comes the daunting prep work. Students spend an entire afternoon lining the big dining room hall with plywood exterior, to which heavy plastic is stapled. This protects the carpeting from being damaged by the copious amounts of foam that gets pumped into the room throughout the evening.

Near midnight, the room looks like a disco Slip ’n Slide. Partygoers in flip-flops and swimwear dance to the live DJ while, outside, the line at the door swells. It’s been said that the Mather Lather is a rite of passage for undergraduates, and where else but Harvard can you get so clean while getting down and dirty?