Castles

Emma is right; Welsh castles are the best. But I think Warwick Castle on England is also great. I like Dover Castle too for its view over the English Channel.

Windsor and the Tower are the most easily done if you'll be in London, and both are impressive (I favor Windsor a bit over the Tower.) Both are very old but they're very different experiences as Windsor is still occupied. St. George's Chapel alone (Windsor) is well worth the short trip out of the city.

Check National Trust UK and English Heritage site for info on Castles and Palaces. I like Hampton Court Palace which is a day trip from London. I have to agree with Emma that Wales does have the best Castles with real towers and moats, Etc. You can take the train from London via Chester and visit Conwy. Beaumaris is only 24 miles further, but you would have to bus it or drive. Caernarfon has been restored and has a roof. Harlech is high up and has a great view. I feel that Wales has loads of mystique and is a time trip. Scotland has some great Castles too but is much more of a time commitment and more easily done with a car. It is worth it to train it to Edinburgh to see the Castle which has an excellent museum of the different Military Regiments, and a great view.

Where will you be staying? I hate to recommend a castle in northern England if you will be staying primarily in London.

As usual, Emma and Keith have great answers. I agree with Carroll, Kathy and Kathleen also.

My favorites are:
The Tower of London
Windsor Castle
Leeds Castle
Bodiam Castle
Hever Castle
Warwick Castle
Dover Castle

The only drawback to Leeds Castle is that it was heavily renovated (interior) in the 1920's and 1930's as a home for an American heiress.
Warwick Castle has been renovated, likewise, on the interior. It is owned by the entertainment company that owns Madame Tussaud's Wax Museum in London, so they have added some Disney-like touches to please the tourists and children, such as jousting and a medieval fair in the summertime.
However, the history of Warwick Castle makes it worth the trip out by train to see it.
It's tremendously more interesting if you know the history and the historical figures connected with Warwick.

If I could visit only two castles, it would be
1.--The Tower of London
2.--Windsor Castle

However, Leeds Castle (from the exterior) is more what you would picture as the perfect medieval castle.
Very picturesque, in the middle of a lake.
Bodiam is also surrounded by a moat; a true medieval castle.
It is a shell. The exterior walls still stand, and are magnificent; but the interior is completely gone.

1) Dover Castle
2) The Tower of London

Bodiam and Windsor Castles.

Some of the castles I liked. I think I got all the countries correct. Which you like is a personal choice.
Windsor
Leeds
Bodium
Beaumaris
Bamburgh
Alnwick
Caerlaverock
Dover
Warwick - touristy

Wales
Conwy
Caernarfon
Harlech
Caerphilly
Coch

Scotland
Edinburgh
Dunnottar
Urquhart
Eilean Donan
Craigmiller

I'd put Dover near or at the top of the list. I combined a trip to Dover Castle and Canterbury Cathedral and it was the best day trip I've ever had.

I'm a huge fan of castles and live in England.
If you are London based then highly recommend Windsor Castle, it's an easy train ride out of London and it's the Queens favourite castle.
Dover Castle is a huge site and you really need a whole day exploring as it has an amazing military history.
Arundel Castle is one of my firm favourites and is accessible via train from London and it looks like a proper fairytale castle.
Personally I love some of the smaller, less known castles like Deene Park and Rockingham Castle. Cardiff Castle is fabulous as well; Wales has a lot of Castles but depends on where you plan to base yourself.
I would avoid Warwick Castle like the plague, very much like an overpriced disneyland style castle and the contents are directed towards children.
Thornbury Castle is a great little castle which you can stay in; apparently King Henry VIII and the second wife stayed there.
x

Thanks for all the advise. Do any have guides?

These websites will help:> http://www.castlewales.com
This site will tell you the opening times of most castles in Wales - just type in the name of the castle:>http://cadw.gov.wales/daysout/caerphilly-castle/?lang=en
http://www.english-heritage.org.uk
https://www.nationaltrust.org.uk/houses-and-buildings