Monte Orsa is a nearly 1000 meters high
mountain located near
Viggiù,
Varese, Northern
Italy, touching the
Swiss border (Lat: 45.31607 Long: 11.69678).
During World War I, general Luigi Cadorna, the head of Italian military forces, was absolutely sure that the Austrians would attack northern Lombardia passing trough Switzerland. So he started a huge work to fortify a so-called Cadorna line, that climbed up mountains and had a lot of hidden passages, paths, check points, landmines and all similar stuff. Of course, this proved to be completely irrelevant, because such an attack never took place. Nowadays, if you like mountain climbing, you can visit it, and one of the best places you can see is Monte Orsa: a mountain that is actually an abandoned hidden fortress.
Another interesting story is that of the aliens: in the 70s, when the UFO craze was at its peak, some smart guy living on a mountain that is in front of Monte Orsa started to say that the greys had a base on the mountain, and so people started to gather in his garden to observe the aliens come and pray (while he was selling them Cokes and ice creams). I don't know if anybody ever saw any alien spacecraft landing, but what I know for sure is that the man has built a restaurant.
Nowadays, the only alien you can probably encounter on Monte Orsa is some Albanian or Kurd immigrant trying to enter Switzerland illegally....