manchester square is an 18th-century garden square in marylebone, london. centred north of oxford street it measures internally north-to-south, and across. it is a small georgian predominantly 1770s-designed instance in central london; construction began around 1776. the north side has a central mansion, hertford house, flanked by approach ways; its first name was manchester house — its use is since 1897 as the wallace collection (gallery/museum) of fine and decorative arts sits alongside the madame tussauds museum and wigmore hall concert rooms as single-greatest tourist attractions of marylebone. the square forms part of west marylebone, most of which sees minor but overarching property interests held by one owner (through lease reversions managed as the portman estate) among which many buildings have been recognised by statutory protection (as listed buildings).