One of the most interesting aspects of Slovakia are the number of castles found all over the country. From dark ages to the almost modern time, it's a wonderful trip for anyone interested in seeing castles.
Devín was the first, and it's stood the test of time up until attacks by the Turks in the middle ages. Amazing ruins and loads of history.
My fiance's brother explained this tower supposedly was some kind of "sacrificial spot" where the king sent a lone virgin female. Not sure if it's true, but it makes for a nice story with the Danube in the background.