OPW Heritage Ireland places in County Carlow

Sixteen hectares of Robinsonian garden in County Carlow: lawns and yews to a lake, an arboretum, bog garden and Ice Age Glen walk to the River Slaney, famous snowdrops; free entry, €2 car park, open daily, no dogs in the gardens.

The early Neolithic portal tomb east of Carlow whose granite capstone of over a hundred tonnes is reputedly the largest in Europe; free, open-air, a short flat fenced path from a small car park, no facilities.

Two drum towers and a wall of William Marshal's four-towered keep of about 1210 by the Barrow in Carlow, half blown up in 1814 for an asylum; free, open-air, seen from the path round the mound with information boards, town parking.

St Moling's seventh-century monastery on a wooded promontory above the River Barrow, with a round tower stump, a high cross, ruined churches, a holy well and a Norman motte in the village graveyard; free, open-air.