John Oxenham

John Oxenham ( "John Oxnam", died ) was the first non-Spanish European explorer to cross the Isthmus of Panama in 1575, climbing the coastal cordillera to get to the Pacific Ocean, then referred to by the Spanish as the ''Mar del Sur'' ('Southern Sea').

Departing from Acla (in modern Darién Province), he descended to the Chucunaque River, which Vasco Núñez de Balboa had also used in 1513 to cross the isthmus, first following the coast to the town of Careta, then receiving assistance from the Cimarrones for the crossing itself. Provided by Wikipedia