Relación del último viage al Estrecho de Magallanes de la fragata de S.M. Santa María de la Cabeza en los años de 1785 y 1786... [and] Apéndice a la Relacion..

The full first edition, complete with the separately published Apendice a la Relación (Madrid, 1793) which appeared ten years after the main work and is not present in all copies. This is the best early description of Patagonia and the Straits of Magellan, giving the official account of the two expeditions made by Antonio de Córdoba to 'ascertain the advisability of Spaniards continuing to use the Strait in voyages - the results indicated the negative. After these expeditions the Spanish trade routes were exclusively to east coast ports and then overland to the Pacific ports...' (Hill). As part of this, the Relación provides a general history of earlier voyages of discovery to the Strait. The large folding maps, fine and detailed, are all based on observations made during the Córdoba voyages.

Córdoba's exploration of the Strait of Magellan --recognised then as now an area of strategic and navigational significance -- is accompanied by Vargas y Ponce's summary of the early explorations of the area, mainly from an examination of original manuscripts in the Spanish archives. He discusses various means of navigating the Strait, with detailed sailing instructions, and describes the climate, indigenous peoples and natural history of the region.