As a result of its trade links with Asia, the rest of the Americas, Africa and Europe and the profound effect of New World silver, central Mexico was one of the first regions to be incorporated into a globalized economy. Being at the crossroads of trade, people and cultures, Mexico City has been called the "first world city". The ''Nao de China'' (Manila Galleons) operated for two and a half centuries and connected New Spain with Asia. Silver and the red dye cochineal were shipped from Veracruz to Atlantic ports in the Americas and Spain. Veracruz was also the main port of entry in mainland New Spain for European goods, immigrants from Spain, and African slaves. The ''Camino Real de Tierra Adentro'' connected Mexico City with the interior of New Spain. Mexican silver pesos became the first globally used currency.