Park Square is a large garden square or private appendix to Regent's Park in London and is split from a further green, the long northern side of Park Crescent, by Marylebone Road and (single-entrance) Regent's Park tube station. It consists of two facing rows of large, very classically formed, stuccoed, terraced houses with decorative lower floor balconies and a colonnade of consecutive porticos by architect John Nash, and was built in 1823–24. Alike, shorter-length terraces flank its corners at right angles, equally Grade I listed buildings: Ulster Terrace, Ulster Place, St Andrew's Place and Albany Terrace.