The Czech Republic.
I realize that a large percentage of Europeans have probably visited it but I have met few Americans who have either been there or even consider going there. Most Americans just want to visit France, England, Ireland, Spain, Germany, and Italy. Don't get me wrong these are wonderful countries to visit but don't miss the Czech Republic if you can help it!
If you make it to Europe visit Prague!
This elaborate clock was built in the 1300's and still runs! It's incredible.
Their medieval churches are beautiful. It's called the city of 1000 spires for a reason!
Prague is fortunate because it didn't get bombed as badly as other European cities did in World War 2. So check out all the beautiful, old castles, churches and pubs and drink a beer! The Czech Republic is incredible!