1. Edinburgh Castle

Edinburgh's handsome hilltop bastion is Scotland's most popular paid tourist attraction, but it also packs some formidable defences.

2. Cardiff Castle

Dan Jones explores the history of the Welsh capital's landmark, Cardiff Castle, and discovers more about the various incarnations over the centuries.

3. York Castle

In medieval England, the North was ruled from York. Dan Jones explores the history of its castle, from the Viking Jorvik and the Normans, through the dark days of the anti-Jewish pogrom and the imprisonment of the Knights Templar, to one of its most colourful inmates - the legendary highwayman Dick Turpin.

5. Lancaster Castle

Dan Jones visits Lancaster Castle to explore its grisly history of crime and punishment, including the infamous Lancashire Witches trials and the martyrdom of the Jesuit priest Saint Edmund Arrowsmith.

6. Arundel Castle

Dan Jones visits the heart of the English countryside to explore Arundel Castle and the dramatic history of the Earls of Arundel.