Buildings were constructed in quick succession, and by the mid-18th century the area was covered in houses. Much of the land was owned by seven estates – Burlington, Millfield, Conduit Mead, Albemarle Ground, the Berkeley, the Curzon and, most importantly, the Grosvenor. Of the original properties constructed in Mayfair, only the Grosvenor estate survives intact and owned by the same family, who became the Dukes of Westminster in 1874. Chesterfield Street is one of the few streets that has 18th-century properties on both sides, with a single exception, and is probably the least altered road in the area.