Carlow

A Norman river town on the Barrow guarding the road south, its castle blown up in 1814 by a doctor who wanted to convert it into an asylum and used too much gunpowder. Carlow's sugar factory, opened in 1926, was the first industry of the new state — a deliberate act of economic independence.

• Browneshill dolmen · A capstone of some 100 tonnes, the heaviest in Europe, raised by farmers without wheels or metal. Nobody is sure how.
• Dunmore Cave · Where the annals say Vikings massacred a thousand people in 928. Bones of women and children were found inside in 1973 — and a Viking silver hoard in 1999.

All of these are pinned on the Hidden Ireland map.