An 18th-century Arabic fortress is the home of the Parador at Jaen in Andalucia. Its 45 rooms cost from £125 per night B&B through keytel.co.uk.
The largest fortified castle in Europe, Hotel le Château-Fort in Sedan, offers 54 rooms and has a restaurant in its 15th-century battlements. From €109 per night through hotelfp-sedan.com.
Borgo San Marco in Puglia, a 15th-century garrison of the Knights of Malta, has 12 bedrooms offering agroturismo hospitality, from £86 per person per night B&B through essentialitaly.co.uk
The 13th-century Otocec Castle Hotel on an island in the Krka River is a hotel with 16 rooms. Three nights cost £580 per person, based on two sharing, with justslovenia.co.uk, including flights, car hire, B&B and a meal.
The turreted mansion Torri e Merli on the Greek island of Paxos dates back to 1750. Now it has seven suites, priced from €220 per night, minimum three-night stay, through torriemerli.com.
Philip I of Portugal built a fort on the banks of the River Sado at Setubal, now a 16-room pousada. From £82 per night B&B through keytel.co.uk.
West Sussex is the setting for 12th-century Amberley Castle, with its portcullis, towers and curtain wall. It now houses 19 guest rooms. A night here costs £230 at amberleycastle.co.uk.
The 15th-century village fortress of Sveti Stefan is one of Europe's hottest properties now it's under the Aman banner. The 58 rooms start from €800 a night through amanresorts.com.
Four hundred-year-old Château Eza set on the side of the ancient walls of Eze on the Côte d'Azur has 11 rooms from €320 per night through chateaueza.com.
Once the home of Gaelic royalty, the Dromoland Castle in County Clare has existed in some form since the fifth century. Now it's a hotel offering two-night breaks from €395 per person through dromoland.ie.