The Award-Winning Gardens of Birr Castle Demesne in Co.Offaly, and Science Centre are both rich in amazing feats of science and engineering as well as rare trees and flowers, wonderful wildlife, and walks along peaceful rivers and the lake. The Parsons family invite you to explore one of the most extraordinary places in Ireland. Created over generations, it is an environmental and scientific time capsule. The Castle at Birr Castle Demesne is still a private family home, there is no access within the Castle itself. Guided tours of the Castle interiors run from May - August. Tours are suitable for adults only. Science In the early 1840’s, the Third Earl of Rosse designed and built the largest telescope in the world. With this telescope, he discovered the spiral nature of some of the galaxies, and from 1845-1914, anyone wishing to witness this phenomenon had to come to Birr. And they came, in their hundreds, from across Europe and beyond, to observe the stars with Lord Rosse or simply to marvel at this feat of engineering in the middle of Ireland. This Reflecting telescope remained the largest in the world for over 70 years and is arguably the largest historic scientific instrument still working today. This ‘leviathan’ as it is named, remains in the centre of the Demesne as Ireland’s greatest scientific wonder and represents a masterpiece of human creative genius. The Science centre demonstrates how the extraordinary telescope, now magnificently restored, was built in the castle workshops by the people of Birr. Scientific instruments are displayed, alongside interactive models to explain how they were used. Castle Birr Castle dates back to medieval times. There was a castle here built on a motte by the Anglo Normans. The gate tower of this led into the castle bawn and is now the centre of the present building. This central gate passage with its 12’ walls can be seen in the lower floor of the present building. The castle or fortress of Birr was re occupied by the O’Carrolls who held it until the 1580s when it was sold to the Ormond Butlers. In 1620 the now ruined castle was granted to the Parsons family by James I. Rather than occupy the tower house of the O’Carrolls they preferred to turn the Norman gate tower into their ‘English House’, building on either side and incorporating two flanking towers. Sir Laurence Parsons did a large amount of building and remodelling including, probably, the building of the two flanking towers, before his death in 1628. This is all accounted for in our archives. The castle survived two sieges in the 17th century, leaving the family impoverished at the beginning of the 18th century and little was done to the 17th century house.