At the confluence of two rivers near the Guadarrama mountains in Spain is Alcázar de Segovia, one of the country's most distinctive medieval castles. It is known for its unique shape resembling a ...

Caerlaverock Castle has a triangular shape which is unique among British castles. It was besieged and captured on a number of occasions but the best-known sieges were in 1300 and 1640. The first ...