Which are the better places and/or sites to see in Europe that most people probablly wouldn’t think of? In other words, are there many more have to see sites that aren’t mentioned in the history books??

Such as origanal cities or certain cliff peaks, temples, and such.
Also which are the least expencive sites to see wether mentioned in history or not (Like the Leaning Tower of Pisa, Sistine Chapel, …).