This is by no means a comprehensive list but these sites to see have been selected for their general appeal, easy access and reasonable expense.
Berhamsted – across from train station. Site of a Norman castle built during the Norman conquest of England in the 11th century to control a key route between London and the Midlands. 25 mins by car from the hotel.
Links: http://www.berkhamsted-castle.org.uk/ http://en.wikipedia.org/wiki/Berkhamsted_Castle
Sherwood Drive, Bletchley, Milton Keynes, MK3 6EB. Historic site of secret British code breaking activities during WWII. About 50 mins from the hotel (up M-1 motorway).
Gorhambury and Old Gorhambury House:
Off Watling Street, St Albans, Al3 6AH. Seat of the Earl of Verulam, built in the late 18th century by the architect Robert Taylor. The present building replaced old Gorhambury House, built in the 16th century and the home of Francis Bacon, the philosopher and writer.
Deansway, Chalfont St Giles. For the bibliophiles among us: home of John Milton. 30 mins from hotel by car.
RAF Museum, London
Grahame Park Way, London NW9 5LL. History of aviation and of the Royal Air Force. 15 mins from the hotel by car.
The de Havilland Aircraft Museum:
Salisbury Hall, St Albans, Hertfordshire AL2 1BU. 16 minutes by car from the hotel.
Aylesbury, Bucks, HP18 0JH Former home of Ferdinand de Rothschild. 1 hour by car from the hotel.
Warner Brothers Studios:
Warner Drive, Leavesden, Hertfordshire WD25 7LP. For Harry Potter fans, this is where the series was made. Tickets MUST be purchased in advance. 10 minutes by car from the hotel.
The largest and oldest occupied castle in the world, and one of the official residences of Her Majesty Queen Elizabeth 11. 45 mins by car from the hotel.