Bonanza, Spain

Bonanza is a port in the city of Sanlúcar de Barrameda, in the province of Cádiz and the community of Andalusia, Spain.
Fiction.
Neal Stephenson named half of his novel "The Confusion" after the port, and had a character describe it as functioning as a chief treasure port of Spain until 1686, and as losing to Cádiz most of what would earlier have been part of its trade, due to the combined effects of increasing vessel draft and of sedimentation at the mouth the river Guadalquivir.