Lake Massapoag is a 392-acre Great Pond located about a mile south of MA-27 in Sharon. The average depth of Lake Massapoag is 16 feet, the maximum is 48 feet and the waters are typically transparent to roughly 10 feet. The bottom is primarily gravel and rubble with several boulder-strewn areas, some close to the surface, which are usually marked with a buoy. Aquatic vegetation is scarce and largely limited to coves on the southern and western shores. The shoreline is heavily developed with houses that, combined with its location close to population centers and aesthetic appeal, make Lake Massapoag a popular destination during the summer months.

The town of Sharon manages a concrete boat ramp and adjacent parking area at Memorial Park off Pond Street on the Northern Shore of the pond. Passes to park and launch trailered boats can be acquired from the town for a fee. There is also shoreline access at the southern end of the lake on town land off of Lakeview Street.