Syon Monastery (frequently referred to as
Syon Abbey or simply
Sion), was a
monastery of the
Bridgettine Order founded in 1415 which stood until its demolition in the 16th century on the left (northern) bank of the
River Thames within the parish of
Isleworth, in the county of
Middlesex, on or near the site of the present Georgian mansion of
Syon House. It was named after the Biblical Holy “City of David which is Zion” (1 Kings 8:1), built on the eponymous
Mount Zion (or Sion, Syon, etc.).