The most cohesive estate in Dublin was laid out between 1760 and 1850. The land acquired by the Fitzwilliam family was leased as a block from the City Corporation and as it was a single block, this lent it a cohesiveness that was lacking in the Gardiner Estate which was developed and bought in small parcels. Their first project was Merrion street in 1758 which was laid out to run parallel to Kildare Street and backing on to the gardens and garden front of Leinster House, home of the Earls of Kildare. The street narrows at the top where it meets St Stephen's green - a typical happening in Dublin where there was no cohesive planning between various estates. It was quickly built on and plans were made for Merrion Square using Merrion street as one side. The square was designed by James Ensor, the planner of Rutland Square and was designed to be 1500 ft long. As built it was 1150 x 650 and the positioning of exit streets at the corners laid the plan for the rest of the estate. Of this was laid Mount Street Upper and Mount Street Crescent as well as Fitzwilliam Street. Fitzwilliam Street forms the eastern side of both Merrion and the later Fitzwilliam Square and is a long expanse of Georgian architecture terminated by Holles Street Maternity Hospital. Holles Street was designed to run of the square from the corner but was dislocated to allow for the building of Antrim House, now the site of the Hospital. Fitzwilliam Square was designed from 1789 but was not developed until the first decades of the 19th century.