[2][3][1] In 1236 Sultan Yaghmorasan (ruled 1236–1283), the founder of the Abdalwadid dynasty of Tlemcen, added the mosque's minaret near its courtyard.

[3] The prayer hall is divided into 13 naves or aisles by 12 rows of horseshoe arches running perpendicular to the southeastern qibla wall.

At this aisle's middle point, in front of the second row of transverse arches, is an ornamental ribbed dome, likely added by Yaghmorasan in the 13th century.

[3] The intricate ribbed dome in front of the mihrab is considered a highlight of Almoravid architecture and dates to the renovation of Ali ibn Yusuf.

[1][6] The structure of the dome is strictly ornamental, consisting of multiple ribs or intersecting arches forming a twelve-pointed star pattern.

It is also partly see-through, allowing some outside light to filter through a screen of pierced and carved arabesque and openwork decoration that fills the spaces between the ribs.

[8] The four facades of the main shaft of the minaret are decorated with carved panels of sebka motifs springing from engaged columns below.

[10] The largest and lowest part of the chandelier had a circumference of around 8 metres (26 ft) and was made of cedar wood clad with sheets of copper that were pierced with floral motifs.

[11] Its remains were moved to a local museum and a replacement inside the mosque was created in the 20th century by Mohammed ben Kalfate, a metalworker and artisan from Tlemcen.

[1] The celebrated ornamental dome and elaborate decoration added to the mosque by Ali ibn Yusuf, however, is considered exceptional and an important testimony of Almoravid craftsmanship which has rarely survived elsewhere.

[1] Jonathan Bloom remarks that the evidence simply suggests that the Almoravids, especially at the height of their power and culture under Ali ibn Yusuf, could afford to import craftsmen from Al-Andalus to work on their new monuments in North Africa.