La città sopra il mondo

Baron Icaro La Plume’s new plane is called the “Flying Catamaran”. Even Zagor and Chico (though reluctantly) have boarded it but, because of a storm, they have to land on a very high mountain. Ol Undas, a technologically advanced city founded by the survivors of an ancient civilization, is located on its summit. There is a fight for power in Ol Undas and even our friends are involved…

Zagor and Chico stumble upon a colony of descendants of Atlantis (or Mu, or a mix of both) located on the mountain. According to Martin Mystere there are 4 or 5 colonies on the mountains around the globe, one on Mount Olympus (where there is actually a laboratory of Atlantis) and one in South America ( Ol Tezuma , perhaps one Mister No came across in 1983).