This was a superb cartoon, made in 1982 and set in 1532. The lead character was a boy called Esteban who knows very little about his background and doesn't know who his parents were. Whilst on a trip from Spain to the New Americas, Esteban meets up with another boy called Tao and a girl called Zia.
All three children are searching for something, Esteban and Zia are both looking for their fathers and Tao is looking for his peoples / tribe. The trail for all three children leads to the Mysterious Cities of Gold and they are accompanied by Mendoza, the navigator, on their journey.