Hackness Martello Tower and Battery

The Crockness Martello Tower on Hoy, Orkney, Scotland, was built at

The Dwarfie Stane is a megalithic chambered tomb carved out of a

Located on at cliff edge at Isbister on South Ronaldsay in the Orkney

The Castle of Mey (formerly Barrogill Castle) is located in Caithness,

The Old Man of Hoy is a 449-foot (137m) sea stack on the island of

Duncansby Head is the most north-easterly part of the Scottish

The surviving Standing Stones of Stenness form an impressive Neolithic

Unstan (or Onstan, or Onston) is a Neolithic chambered cairn located

The Alba Carolina Citadel (Romanian: Cetatea Alba Carolina) is a

Fort Copacabana (Portuguese: Forte de Copacabana, IPA: ]) is a

Kilitbahir Castle (Turkish: Kilitbahir Kalesi) is a fortress on the

Menara Santo Vicente (Portugis: Torre de São Vicente) atau Menara

Castillo de Alcalá la Real (or Fortaleza de La Mota) is a castle in