The city of Krakow excavated its market square in the past decade as an archaeology project. Instead of simply reburying everything, they made an underground museum and covered it over to make the square look normal atop. The museum is pretty neat. For one thing, they allow only a certain number of people in it at a time. This means you don't feel as crowded or hurried as most places. It also has a lot of tech stuff in it to make it seem more alive. The first four photos here are of some of those. Then there are a lot of finds from the square displayed either in cases or in ways that show how they were used. It's a great experience.