The Tower of London is a great place to visit for ...

The Tower of London is a great place to visit for History lovers. If you are limited on time, skip the free Yeoman Warder Guided Tour, that's included with your ticket price. Go straight to the Crown Jewels Exhibit and begin your wait. It's worth every minute you will spend in the long, long... long line. You can spend as much 45 minutes before getting into the building and then wait an additional 15 minutes waiting in line inside.
Second place with the long line is the Torture Tower. Well worth it, small and over crowded. Not many torture exhibits, but the ones that were there certainly effective.
The Bloody Tower is up next, but it is not as gory as some would suggest.
The Imprisonment Tower was great for the History guys.
It is possible to spend a day here, if you want to.