In the suburbs of Toledo San Nicolas is located in a former mosque of Cristo de la Luz. This is one of the best preserved mosques in Spain and one of the oldest structures on the territory of Toledo. The mosque called Bab al-Mardum, was built in 999 under the leadership of the Arab architect Moussa ibn Ali de Saad, whose work was greatly influenced by the Great Mosque of Cordoba.

There is evidence that the mosque was built on the remains located here earlier Visigothic church. After the expulsion of the Arabs from Toledo by King Alfonso VI of the mosque it was converted into a Christian church dedicated to the Saviour and called Cristo de la Luz.

The facade of the building from the south-west side is decorated with an inscription indicating the time of its construction, and extols the greatness of Allah. North facade attracts the attention of the original brickwork and colored tiles. Entrances to the building are decorated in a horseshoe-shaped arches. The upper part of the facade is decorated with original frieze, roof of the building is supported by elegant brackets. Thanks to the many rather large windows of the church interior is well illuminated by the light. In one part of the inside of the church is the body of nine domes, are supported by rows of columns decorated with Visigoth capitals. Particularly noteworthy are the frescoes located inside the church and belonging to the 13th century. In the process of converting the mosque into a Catholic church it was added to it the apse, in the building which used the same stone and the same decoration as the main building.