2 days in Prague - essentials/tips!!!

Castle hill is a great visit, the cathedral in particular was impressive. Make sure and walk down the hill, don't take the bus back. We enjoyed the Lobkowitz collection, fascinating story of an American who went back to reclaim his Czech heritage and property, including art collection, that had been confiscated by the Nazis. Charles Bridge visit late or early. Old town and the main square are a must. Museum of Communism and Mucha visit were great too. I think the Little Quarter was really nice to just stroll around, although it's a steep hill and all the shops were closed by the time we got there. I visited in my 40's, but sure how much of this appeals to someone your age. With relatively little time you could do worse that just walking around enjoying the ambience and selectively visiting a couple of sights that call out to you.

http://www.prague.net/
this is a great website for info on what to see and do.
I have no idea of your interests and I am more than old enough to be your grandfather so what I am interested in may be totally different to you.
If you are into skate boarding /rollerblading etc . head to the Metronome in Letna park, you will be able to see it from the river and there are steps up to it.this is where all the younger folk hang out ,it is the base of an old Stalinist monument, great views from there too.You are a bit too young for the Prague drinking culture but a vist to the beer garden can be fun and you don't have to drink beer.I like the one in Letna Park and also riegrovy Sady,.
But give me an idea of what you are into and I will see if I can help. I am back in Prague at the end of the month and then again end of June beginning of July

Eighteen years is legal age for drinking alcohol in the Czech Republic. If you don't look under fifteen they are not carding. Beer in Prague is very good and cheap. Don't overdo it.

Wander around Old Town Square and up to the Castle via the Charles Bridge. Go take a peek and the Jewish Cemetery. Try to catch a performance of Jazz Efterratt. Great city you'll love it!

Our kids loved the Jewish Cemetery. Closed on Saturday so plan for that. There also in the castle area was a reconstructed area from medieval times with a weapons museum that they liked, They were 13 and 15. They liked going on Charles bridge and watching street performers in Old Town Square.