Overview
For seventy years the largest telescope on Earth stood not in Greenwich or Paris but in a walled estate in the middle of County Offaly. The 3rd Earl of Rosse’s 72-inch reflector, the Great Telescope, is still the reason most people come to Birr, and it anchors Birr Castle Demesne on the edge of the town. Birr itself is a designated Irish Heritage Town of around 5,700 people, laid out with the measured elegance of Georgian planning around Emmet Square, Oxmantown Mall and John’s Mall.
If you only have a couple of hours, spend them in the demesne and leave the town walks for afterwards. The Birr Theatre and Arts Centre on Oxmantown Mall, in a building dating from 1888, runs a steady programme of drama, music, comedy and dance if you’re staying the evening.
A family of inventors
Birr began as a 6th-century monastic settlement founded by St Brendan on the Camcor; St Brendan’s well still survives in the demesne grounds. An Anglo-Norman fortification followed in 1208, and the area stayed under O’Carroll control until the Plantation of Ely O’Carroll in 1619, when Sir Laurence Parsons took the estate. For nearly three centuries the town was known as Parsonstown, and the Parsons family – later the Earls of Rosse – have lived at the castle since the 1620s.
They were a remarkable household. William Parsons, the 3rd Earl, built the Great Telescope in the 1840s and it held the record for the largest in the world until the early 20th century. His wife, Mary, Countess of Rosse, was a pioneer of early photography and kept one of the oldest surviving darkrooms anywhere. Their son, Charles Algernon Parsons, went on to invent the steam turbine, which reshaped both ship propulsion and electricity generation. The Camcor did its bit too, driving the sawmills, corn-mills and early generators that ran the estate before the national grid reached it.
What to see and do
Birr Castle Demesne and the Great Telescope
The demesne spans 120 acres with more than 5,000 species of trees and plants, 10km of trails along two rivers, a lake and a waterfall, Ireland’s tallest treehouse, and the restored c.1820 suspension bridge. The Great Telescope stands at its heart; you can walk right up to the 58-foot tube. The gardens have collected horticultural awards over the years, and the layout is easy going, with plenty of seating.
The castle interior is open only on guided tours, and only in the warmer months: mid-May to early September, Monday to Saturday, at 11.00, 12.30 and 14.00. The gardens and Science Centre keep much longer hours – daily from 09.00 year-round, closing somewhere between 5pm and 6pm depending on the season.
The Science Centre
Set in the castle’s restored 18th-century stables, Ireland’s Historic Science Centre turns the Parsons legacy into hands-on exhibits on early photography, mechanical engineering and astronomy. A certified lift reaches the first floor, and it makes a reliable rainy-day stop with staff on hand to explain the engineering behind 19th-century optics.
Two short town walks
Two signposted routes start from Emmet Square and take about an hour between them. The Birr Fan Trail (1.2km) threads the Georgian town centre, past the 1747 market cross and along Oxmantown Mall, the avenue that once linked the town to the castle’s service yards. The Riverbank Walk (1.1km) follows the Camcor through Mill Island, passing the weir beside St Brendan’s Catholic Church – a dependable photo spot.
Angling and wildlife
The Camcor’s spring-fed water and old watercress beds keep a healthy trout population, and the riverbanks draw wading birds after the level rises in wet weather.
Practical information
- Parking: there is no parking inside Birr Castle Demesne. Use the public car park at Marian Hall directly opposite the entrance, or park on-street in the town.
- Getting there: Birr is about 90km west of Dublin via the M6 and N52. There is no railway – the station closed in 1963 – so you’ll arrive by car or bus.
- Facilities: cafés, restaurants and shops cluster around Emmet Square; the demesne has its own café, open from 10.00.
- Best time to visit: late spring to early autumn for the gardens and trails. The Science Centre holds up well in cooler months.
Nearby attractions
- Clara Bog – a raised bog with boardwalks and a visitor centre, a short drive north.
- Clonmacnoise – the early-medieval monastic site on the Shannon, about 30 minutes away, with high crosses, round towers and the callows.
Book a castle tour online before you arrive: the slots are few and fill fast on weekends and during school holidays. And remember the demesne itself has no car park – aim for Marian Hall opposite the gates.