Glastonbury is a town and civil parish in Somerset, England, situated at a dry point on the low-lying Somerset Levels, 23 miles south of Bristol. …Glastonbury is a town and civil parish in Somerset, England, situated at a dry point on the low-lying Somerset Levels, 23 miles south of Bristol. The town had a population of 8,932 in the 2011 census. Glastonbury is less than 1 mile across the River Brue from Street, which is now larger than Glastonbury.