The 11th-century Bab el Bhar gate in Bejaia

The Bab el Bhar, also known as the Gate of the Sea, is a historic monument in the city of Béjaia in Algeria. It served as the maritime entrance to the city, where boats and small ships entered the port by passing under its large arch.

Constructed between the mid and late 11th century by the Hammadides under the rule of An-Nasir, it was one of the six gates of the wall of Bejaia. The structure incorporates construction techniques used by the Hammadides at the Kalâa des Béni Hammad, specifically the form of the pointed arch and a wall masonry made of an alternation of rubble stones and courses of bricks.

The pointed arch consists of radiating brick courses resting on horizontal brick courses, which in turn rest on two stone imposts. The gate is topped by a semicircular relieving arch, distributing the weight of the wall on either side of the pointed arch.

Currently, a large part of the gate is buried, making it difficult to determine its exact height, though the opening was intended to reach approximately 10 meters high and 6 meters wide.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons