The Pont du Gard is an ancient Roman aqueduct bridge that crosses the Gardon River in Vers-Pont-du-Gard in Gard, southern France. The Romans built the bridge in 1 AD to carry water from a spring. As you can see it is still in use.
Dun Aengus Stone Fort, Aran Islands, County Galway, Ireland - features massive dry stone walls and a 250 foot sheer drop to the Atlantic Ocean. There are spectacular views of the three Aran Islands and the cliffs of County Clare.