Birr Castle Gardens

The third Earl of Rosse built a reflecting telescope at Birr in 1845 with a metal mirror 1.8 metres across, mounted between two masonry walls - the Leviathan of Parsonstown, the largest telescope in the world until 1917. With it he identified the spiral structure of what are now known to be galaxies, drawing M51 in detail decades before anyone understood what it was. The instrument was dismantled in 1914 and reconstructed in the 1990s; it is on the lawn and is demonstrated. His wife Mary Rosse was a serious early photographer whose darkroom, one of the oldest surviving anywhere, is in the castle, and their son Charles Parsons invented the steam turbine. The science centre covers all three. The gardens hold over a thousand species, a suspension bridge of 1820, and box hedges planted in the 1780s that are over ten metres and hold the record for the tallest in the world. The castle is the family home and is not open.

What you actually see

• The Leviathan - the 1845 telescope, reconstructed and demonstrated.
• The box hedges - planted in the 1780s, the tallest recorded anywhere.
• The science centre - the Rosse telescope, Mary Rosse's photography, the turbine.
• The demesne - a thousand plant species and an 1820 suspension bridge.

When to go

April to October for the gardens at their best; the demesne is open year-round with reduced winter hours. Telescope demonstrations run to a schedule.

Honest expectations

The castle is the family's private home and is not open to visitors - the ticket covers gardens and science centre. The telescope is a reconstruction using the original mirror mounting. Ticketed and a full-price attraction.

Nearby

Birr town is at the gates; Leap Castle and Clonmacnoise are within a short drive.