White Cliffs of Dover and Dover castle

Whether a sight is "worth it" depends on how much time you have and your interests. We found Dover to be quite interesting; but then we were living in London for a year and did a day trip almost every weekend. We're also history enthusiasts. Yes, you can see enough of the cliffs from land. There is an ancient lighthouse on the grounds of or near the castle that has graffiti done by crusaders before embarking. There is also a Roman archaeological site to visit.

It has been many years since I have been to Dover, but I loved the castle. It is a great one to roam around in. You can see the cliffs; it was enough for me.

As has been said it really does depend on your interest in history and there is certainly a lot of history there, it is quite a big site (see picture in the link). I really like the keep, it is very well preserved, but I notice that the main part of it is closed until August 2009.

http://www.english-heritage.org.uk/server/show/nav.14578

One tip, the free WW2 tunnel tours are very popular so book your time slot as soon as you arrive. If you wait until you are ready you may find that you will have an hour or so wait.

The town itself is not that inspiring but the Roman Painted House is worth a visit (to me anyway)

http://www.aboutbritain.com/doverromanpaintedhse.htm

BTW the lighthouse mentioned is Roman. Also, on a clear day you will see the coast of France.

I'm not positive, but I think there are opportunities in Dover to take boat tours to see the cliffs. As to "worth it," we took the ferry last June from Calais to Dover, just so we could see the cliffs. We stared at them for the entire 90 minute crossing (we are very into British history). However, we were joined the last thirty minutes by at least a hundred Brits, also staring in awe at the cliffs. Obviously, those cliffs have an emotional draw.

Dover is a nice day trip. Provided the weather is good you can see lots of the cliffs. There are also boat trips of variying lengths. The castle is wonderful. They often have special events. When we were last there they had a falconry exhibit. The hosts were dressed in Elizabethian period costumes and they did demonstrations with the various birds. Sometimes they have archery contests,etc. You can get the train to Dover from Victoria Station. It is the same route that goes to Canturbury. If you find Dover isn't enough of a day for you- stop in Caturbury on the way back to London!