In two hours by train north of London is the city of York, who keeps in its ancient walls of the 1900 year history. The Romans built the city in 71 AD. Vikings occupied it in 866. Go to the Yorkshire Museum and Gardens, to see what was left behind the Romans and the Vikings (apparently, they left the place, he took with him quite a bit). Then, visit the Museum of York Castle and leisurely explore the past 400 years of history of the city.