The Great Mosque of Herat is a mosque in the city of Herat, in the Herat Province of north-western Afghanistan. It was built by the Ghurids, under the rule of Sultan Ghiyath al-Din Muhammad Ghori, who laid its foundation in 1200 CE. Later, it was extended several times as Herat changed rulers down the centuries from the Kartids, Timurids, Mughals and then the Uzbeks, all of whom supported the mosque. The fundamental structure of the mosque from the Ghurid period has been preserved, but parts have been added and modified. The Friday Mosque in Herat was given its present appearance during the 20th century.

The entrance corridors are to either side of this, but they are frequently locked outside the main prayer hours, forcing visitors to gain access to the mosque proper via the small street entrance on its northern wall. This is actually a more atmospheric choice, as the cool dark of the entrance corridor suddenly gives way to a bright sunburst of colour as you enter the main courtyard. The mosque is laid out in a classical plan of four iwans (barrel-vaulted halls) with arcaded walls around a central courtyard nearly 100m long. Two huge minarets flank the main iwan. Almost every square centre is covered in breath-taking mosaic, surrounded by blue bands of Quranic script. Only the simple whitewash of the iwans adds a note of modesty. The minarets, with their repeated bands of stylised flowers, arabesques and geometric patterns are simply dizzying. The mosque was originally laid out by the Ghorid Sultan Ghiyasuddin in 1200. Originally it would have had quite a different appearance, as the Ghorids preferred plain brick and stucco decoration. The Timurids restored the mosque in the 15th century and introduced the bright mosaic, but by the early 20th century so much of this had been lost that visitors remarked on the mosque’s dullness. The lavish tiling that now covers the mosque is the product of the mosque’s tile workshop, an ongoing restoration project since the 1940s. While many of the mosaics are based on Timurid originals, the workshop has also introduced its own designs, colours and calligraphy.

The initial plan of the mosque was by the Ghurids. The Ghurids built the entire mosque using brick. The layout is a typical 4-iwan plan with an interior courtyard and a water basin. The qibla orientation towards the west was adhered to, although this deviates from the correct direction to Mecca by about 20°. The main iwan was covered by vaults. It formed an axial cross with the other three iwans on each side of the courtyard. These three iwans were intended as meeting and teaching places for smaller audiences. Mosque at present

The mosque complex is 180 meters long and 120 meters wide, covering an area of about 21,600 square meters. Besides the four large iwans, there are 460 domes, 444 pillars, and 12 minarets (17–36 meters tall). These elements are grouped around the central courtyard (82m by 60m).Pishtaqs, the gateways to the iwan, underline the spatial importance of the iwans. Together with the depth of the iwans, they provide a large surface for ornamentation. A significant part of the present mosque is covered with glazed tiles in bright colours according to Timurid tradition. Decoration from the Ghurid period in the present mosque.

In the southern and western iwan interior, decorative elements of the Ghurid period are uncovered. Made from stucco, they are stamped with floral and geometric patterns. Stucco is a material for moulding ornaments. At the southeast corner of the mosque is the Ghurid portal. It has not served as a portal since unknown times. On both sides of the archway, Kufic inscriptions are displayed. This style of Arabic script is typical of Ghurid period inscriptions. The vertically placed bands of inscriptions are made of terracotta and worked into the base’s mortar like a mosaic. On the front, they are glazed blue, contrasting with the light red brick tone of the background. The sidewalls of the portal are decorated with geometrical brick mosaic, interspersed with blue glazed tile plugs.