Sixteenth-century mapmakers back in Spain mistakenly confused the names, so that in the end the port became San Juan and the whole island was called a rich port ; once on the maps, the names stuck.
The island was originally named Puerto Rico, but it was renamed San Juan in 1963.
mnli hypothesis: The island was originally named Puerto Rico, but it was renamed San Juan in 1963. premise: Sixteenth-century mapmakers back in Spain mistakenly confused the names, so that in the end the port became San Juan and the whole island was called a rich port ; once on the maps, the names stuck.