So yes.... you can of course read about the Strasbourg Cathedral on the web. It is, they say, one of the finest examples of gothic architecture around (though it also has roman elements etc). Not surprising, since it was apparently under construction for more than a couple of hundred years.
The cathedral is also famous for its astronomical clock. It is a completely over-the top take on the traditional cuckoo clock! At noon (after a film that shows you all the details that you will later see), you get to watch the clock in action [a crowing rooster, a small angel turning over an hour glass, death ringing on a bell with a giant bone, and Christ giving his blessing to each of the 12 apostles who come out one after the other in procession. Impressive. You can check out other tourist's attempts to capture the clock here.