London and Dublin beginning of December

The Tower of London is a great place to spend some time.

It sounds corny, but a good way to start a visit is to get on one of the red double-decker tour buses that makes a big circuit through town and has a guide narrate the sites along the way.

They aren't cheap, but they are a good way to get a look at all the major sites (in case you don't get time to go to each individually) and get the lay of the land.

I've been to London 4 or 5 times, and I've never been to Stonhenge. It takes too much time for something I have little interest in, when there are so many better things to see and do in and around London.

The regular city buses don't have a guide, of course, but they are also a cheap way to get around and see some sites without pounding the pavement. Find a route or two that passes several tourist sites. Use your Oyster card to swipe when you get on; it charges you a couple bucks or so to ride as long as you want.

Check the "open to the public" schedule for Westminster Abbey when you get there and plan your visit. They sometimes close for special events, and around Christmas could get you burned on that. Don't trust the website. Call or go by and read the sign.

As everyone in the post has said, it really depends on what you want to do.

I would agree with Tower of London/Tower Bridge being at the top of the list. It houses the Crown Jewels, as well as being one of the most historic places in the city.

For Museums, you really can't go wrong with the British Museum, though I really enjoyed the Victoria & Albert Museum in Westminster.

With Art Museums, I thoroughly enjoyed the National Gallery, and went to the Tate Modern and would recommend it if Modern art is your thing.

Both Westminster Abbey and St. Pauls are breathtaking but you should check to see if anything is going on.