This remarkable 12th-century fortress was once known as the Crypt of St. John—before excavation, it was erroneously thought to have been an underground chamber. The dimensions of the colossal pillars that support the roof (girded with metal bands for extra strength) make this one of Israel's most monumental examples of Crusader architecture. It's also one of the oldest Gothic structures in the world. In the right-hand corner opposite the entrance is a fleur-de-lis carved in stone, the crest of the French house of Bourbon, which has led some scholars to suggest that this was the chamber in which Louis VII convened the knights of the realm.
Just outside this room is an entrance to an extremely narrow subterranean passageway. Cut from stone, this was a secret tunnel that the Crusaders probably used to reach the harbor when besieged by Muslim forces. (Those who are claustrophobic can take an alternate route, which goes back to the entrance of the Turkish bathhouse and continues from
there). Emerge in the cavernous vaulted halls of the fortress guard post, with a 13th-century marble Crusader tombstone at the exit.
Here, a series of six barrel-vaulted rooms known as the Knights' Halls has been discovered. Arrows point the way through vast rooms filled with ongoing reconstruction work, huge marble columns, and archaeological pieces from the past. Above this part of the Crusader city stands the Ottoman citadel, which you can glimpse from the courtyard. Built by Dahr el-Omar in the 18th century on the rubble-filled Crusader ruins, the citadel was the highest structure in Akko.
The different factions within Akko's walls probably sowed the seeds of the Crusaders' downfall here. By the mid-13th century, open fighting had broken out between the Venetians and Genoese. When the Mamluks attacked with a vengeance in 1291, the Crusaders' resistance crumbled, and the city's devastation was complete. It remained a subdued place for centuries, and even today Akko retains a medieval cast.