Carnegie Mellon University students painted a fence for 70 years, with the Guinness Book of World Records calling it "the most painted object in the world" with six inches of paint covering it. It would collapse under the weight of all those coats in 1993, but a new concrete fence was built to replace it. Today, students carry on the tradition of painting the Fence at night.
Fences used to surround a bridge over a ravine on the property when the Carnegie Institute of Technology was established in Pittsburgh in 1900. The bridge was a popular meeting place for students at the time. Further construction would lead to the ravine being filled in over the early years of the school, and the bridge and its fences no longer being necessary. To commemorate the favored meeting spot, the graduating Class of 1923 built a picket fence on the site to keep tradition alive. However, school officials decided that it was an eyesore and should be brought down. The night before the fence was to come down, a fraternity painted it with a party announcement, and due to the fence’s central location on campus, it was the largest party in school history. The administration yielded, and the Fence continued to be a billboard for student groups, becoming covered with layer upon layer of paint.
The painting would continue for 70 more years until it collapsed under the weight of its painted layers in 1993. To carry on the tradition, a steel-reinforced concrete fence was built on the site, and students continue to paint it to this day. Tradition dictates that the Fence must only be painted at night, from midnight to 6 AM, in its entirety, using only brushes. If a group wants to keep the message up over a few days, the Fence must be guarded around the clock with at least two students. The Fence has once again accumulated four inches of paint covering it, catching up to the record set by the old Fence one layer at a time.