The Tower of London, London, England © Freefoto.com

Alwick Castle, Northumberland, England © Freefoto.com

Bamburgh Castle, England © Freefoto.com

Edinburgh Castle, Scotland © Freefoto.com

Eileen Donan Castle, Scotland © Freefoto.com

Carlisle Castle, Scotland © Freefoto.com

Arundel Castle, England © Freefoto.com

Caernafon Castle, Wales © Freefoto.com

Windsor Castle, England © Freefoto.com

Harlech Castle © Freefoto.com

Warwick Castle, England © Freefoto.com

Lindisfarne Castle, Scotland © Freefoto.com

Dover Castle, England © Freefoto.com