On Piano di Sant'Andrea stands the impressive Porta Soprana, dating back to the 12th century and featuring two towers connected by a pointed arch.

The gate was called Superana, because it was placed in a dominant position on the hill of Sant'Andrea, one of the five gates opened in the wall, known as 'del Barbarossa'.

The walls were actually built to preserve the autonomy of the Republic from the expansionistic intentions of Federico il Barbarossa, Emperor of the Holy Roman Empire, after whom they were named. The execution of this important work, finished in a very short time between 1155 and 1159, required both tangible and monetary input from the majority of Genoese citizens.

"If you come in peace, you are allowed to touch these doors"; it is inscribed on an epigraph affixed to the entrance gate, which in a medieval Latin full of wordplays warns the stranger not to have aggressive intents, because Genoese people know how to defend themselves very well.