We don't have synonyms for henges yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hanges, hedges and henge.
(n) :
A prehistoric enclosure in the form of a circle or circular arc defined by a raised circular bank and a circular ditch usually running inside the bank, with one or more entrances leading into the enclosed open space.
(n) :
A prehistoric enclosure in the form of a circle or circular arc defined by a raised circular bank and a circular ditch usually running inside the bank, with one or more entrances leading into the enclosed open space.