While we're talking about travel in Europe, another unique and exciting destination to visit would be Spain. After checking out all of the nice hotels in Spain, and booking one for your vacation, you can visit Muralla de Avila, which is the fortress wall surrounding the city of Avila. I'd like to see Torre de Bujaco in Caceres, which is a square Arab tower that predates the Crusades and is open to the public.
You could travel to Barcelona (there are several very nice hotels in Barcelona) and visit La Sagrada Família (a massive Catholic basilica that's still unfinished), La Boqueria, an open-air market or the Gothic quarter, with it's many points of interest dating from the Roman era & the Middle Ages.
If you choose among the hotels in Madrid instead, you can visit the Prado museum, the Royal Botanical Gardens (which were originally undertaken by Carlos III & were inaugurated in 1781) or The Royal Palace, which is still used symbolically during official ceremonies & is open to the public for tours.
Seriously, there are some really beautiful sites in Spain, and a lot of amazing architecture to visit, too.