It's a must do in London. You can walk through all...

It's a must do in London. You can walk through all the towers and battlements learning about the evolution if London and the Castle. You can walk in the main keep where there is a nice display if armor and weapons from past times.

The crown jewels are in there as well so I think it's worth it in itself to just go see those. They even bring you through the history of the gems and jewels found on the crowns.

I reccomend going early. It gets very busy around lunchtime. I would leave about 1hr 30min if you see everything quickly and add 45min if you take your time.

(Its also a great place to photo op with a Royal Guard.)