57.814, -8.581

It is not Stonehenge and the Internet is not helpful!

From Wikipedia, the French version:

Dùn est une île inhabitée du Royaume-Uni située en Écosse, dans l'archipel de Saint-Kilda.

Further Internet searches for:

• Cnoc Glas - a cottage in Ireland.
• Conchair - nothing.
• Bioda Mor - Dun is a narrow rocky ridge which rises direct from the sea. Home to vast numbers of puffins, it provides some shelter for Village Bay.