Formerly called Gelding Square, is near the end of Piccadilly. The access to it is dirty; and, altogether, it has no very high claims to distinction for its beauty or magnificence. It was built soon after the Revolution of 1688-9, in what were then called the Pest-house Fields. In those fields, Lord Craven built a lazaretto, which, during the dreadful plague of 1665, was used as a pest-house, and hence arose the name. Carnaby Market also occupies a considerable portion of what previously constituted a dirty waste.
Source: Leigh's New Picture of London. Printed for Samuel Leigh, 18, Strand;
by W. Clowes, Northumberland Court. 1819