Clay Pit Pond, also known as Claypit Pond, lies between Concord Avenue and Belmont High School. Its waters are notoriously unclean and incidents of students swimming in the pond have resulted in infection. It was used in the past as a source of clay for making bricks. The large pit was flooded with water after operations ceased, leaving some equipment behind. Some speculate that an intact steam shovel lies hidden beneath its surface.

After a recent problem with flooding, which raised the water level up to a nearby road after a large rainstorm, a new drainage system was implemented. Nevertheless, the pond overflowed onto the road after two days of rain in March 2010, closing down the high school.