The Peral Submarine is Cartagena's great engineering curiosity. Designed by Isaac Peral in the 1880s, it was one of the earliest practical electric-powered submarines and is now displayed as part of the naval museum complex.
It is a compact exhibit but a memorable one, especially because Peral was born in Cartagena. The submarine gives the city a technological story to sit beside its ancient and naval histories, and children usually find it more immediately gripping than another wall of dates.