Thonburi is an area of modern Bangkok. During the era of the Ayutthaya Kingdom, its location on the right (west) bank at the mouth of the Chao Phraya River had made it an important garrison town, which is reflected in its name: thon (ธน) a loanword from Pali dhána 'wealth', and buri (บุรี), from púra, 'fortress'. The full formal name was Thon Buri Si Mahasamut. For the informal name, see the history of Bangkok under Ayutthaya.