Lisfinny Castle likely dates to the early-16th century. Built by the Earl of Desmond – the head of the Fitzgerald family – it was a stronghold during the 1579 Desmond Rebellion. It was then granted to Sir Walter Raleigh. Raleigh sold the castle to Sir Richard Boyle – the father of Robert Boyle, the scientist and mathematician best known for his discovery of Boyle’s Law – who began smelting iron in Tallow. This gave the town its name, ‘Tulach an Iarainn’ in Irish, which translates to ‘hill of iron’. This industry remained in the area until all the surrounding forests had been consumed for charcoal. The castle is now in ruins.