The National Trust in Scotland has various properties that it rents out. You might find something there (I suspect the English equivalent probably does the same). Alternatively, there are lighthouses that you can rent and that might fit the bill.

It will cost you a bit, but why not contact the hotel GREAT FOSTERS in Egham, and ask about their Tower Room ....... it has a spiral staircase, but you have to go down it to use the loo!

Try the Landmark Trust - they have a few towers.

They have a Tower in the Towers Hotel near Swansea. Lovely hotel, great breakfast and fantastic facilities. Not cheap for the Tower though £250 a night for the top floor.

Our award-winning Tower houses three bespoke suites, ideal for romantic getaways and special occasions such as weddings and anniversaries. Each is individually decorated with beautiful views of the expansive hotel grounds, surrounding wooded areas and coastline.

http://www.thetowersswanseabay.com/

Thanks for all the replies, the Mrs wants to try all of them..........Good thing I haven't got Vertigo

try insulting the Queen