The architectural aspect of Prague is of course astonishing, but I'm sure you heard that already? So let's focus on the character of the city.
Although my stay in Prague was limited to just 1,5 day, it was enough to feel the city's atmosphere. For someone, who is already used to living in a small, peaceful town, I felt a cultural shock when I walked through the city of Prague. The capital of Czech Republic is a loud, vivid, liberal place, where many young people come to celebrate, have fun and enjoy their time.
You can hear all different languages, see thousands of tourists, dressed up Scots, singing Britons in the pouring rain, peaceful marches, screaming Spaniards, Vltava river covered by people on paddle boats and surrounded by cafes and bars, open air festival, live band music on each corner, people dancing barefoot and everyone seems to be happy and free.
If you are a fan of festivity and search for an adventure, I think Prague might be the right place to go. I wouldn't recommend going there for site seeing in the middle of the summer though, because it's way too hot for that!