SNIPPET: County Offaly (King's Co.) lies in the heart of Ireland between the Slieve Bloom mountains and the River Shannon and is now a gentle rural part of Ireland. This was the territory of the Ely O'CARROLL clan who ruled here from the 9th century, and there are still signs of the many castles, monasteries and other fortifications from those times. Visitors will also find small, well-maintained towns and villages which welcome walkers, birdwatchers and garden enthusiasts. The Georgian town of Birr (formerly Parsonstown) has elegant 18th century townhouses and a dignified square. The town's glory is surely the demesne of Birr Castle, home to the PARSONS family, the Earls of Rosse. The gardens of Birr Castle are a treasure trove of plantings - there are formal gardens with tumbling roses and intricate flower beds incorporating the family monogram, swathes of colour throughout the year and the tallest-growing box hedges. But in one part of the demesne stands what was the largest telescope in the world, when it was first built in the 1840s by the third earl, William PARSONS (1800-67), an astronomer with connections, apparently, to both York, England, and Monkstown, Co. Cork. Building of the telescope had to be suspended during the Great Irish Famine, but in 1847 it was put into service. Carefully restored as part of a millennium programme, this Leviathan, as it became known, is astounding. The PARSONS family interest in things scientific is explored further in the Historic Science Centre where astronomy charts and photographic equipment, belonging to Rosse ancestors, are on display. PARSONS named the Crab Nebula and The Rosse Crater on the Moon was named after the third earl.