United Kingdom
This ancient military fortification is still in use by the army, but also functions as a monument and museum of army life at the fort. It's visually stunning and fascinating for military buffs, but just as fascinating for lovers of nature - dolphins and numerous types of wild sea bird can be seen. Bring your binoculars.
Ardersier, near Inverness (easily accessible by Tourist Bus from Inverness town centre)
Search Been there