It is sometimes misspelled as Salisbury, or Solisbury, perhaps because of confusion with Salisbury Plain (a plateau in southern England), or the city of Salisbury. Salisbury and Solsbury can be difficult to distinguish in speech; Salisbury is often pronounced Saulsbury, and sometimes the a in Salisbury is pronounced as an o, and the i is elided, making the pronunciations of the two words practically identical. The name 'Solsbury' may be derived from the Celtic god Sulis, a deity worshipped at the thermal spring in nearby Bath. A geological map by Horace B Woodward in the back of the 1888 'Handbook of Bath' labels the hill as 'Stilisbury Hill'.