"Wilton castle is a 19th century castellated residence set on the banks of the Boro River specializing in luxury accommodation in the sunny south-east of Ireland." Of course, this luxurious experience comes at its own price. Being one of the most expensive Airbnb's on our list, this castle costs $1,434 for one night, but there is a two nights minimum stay. If it makes you feel any better, you can come here with 13 of your friends. After all, it is a castle.