The Registan Square ensemble in Samarkand is formed by the Ulugh Beg Madrasa, 1418-1422, the Shir Dar Madrasa, 1619-1636, the Tilla Kari Madrasa and Mosque, 15th-16th century, and the 18th century Chor-Su domed market. Earthquakes, seasonal temperature extremes, normal depreciation of the buildings and the economic crises of the 18th and 19th centuries had left the complex in a ruined condition. Domes and portals were partially or, in some cases, totally destroyed, the minarets were dangerously inclined, and façades in some places had lost 70-80% of their ceramic tile coverings. Structural repairs and straightening of the minarets had been enacted on two previous occasions, in 1923 and in 1932, however, the major restoration works were undertaken between 1967-1987. Restoration work was based on extensive studies, including archaeological excavation, probing and measurement, archival research, and epigraphic studies. 90% of the project was funded from national government sources and the remaining 10% from local government sources.
The ensemble consists of three massive-scale blocks, each with central courtyard. Each of the three blocks, now totally restored, presents its main entrance archway to the square. The archways are flanked by minarets, which reinforce the symmetry of the entrance façades, though the silhouette of the Tilla Kari Mosque, with its turquoise coloured dome, contributes a powerful eccentricity to the composition. The ensemble imposes a powerful rectilinear geometry in an otherwise chaotic, but morphologically subtle urban setting. Restoration began only after ancient techniques for the construction of domes and vaults had been mastered. Local ceramic workshops producing glaied tiles, painted majolica, and various coloured, glazed kashi inlay. The strongly geometric nature of ornamental compositions and the epigraphic decoration made it possible to restore partially lost facing on façades and on murals in the interior of the Tilla Kari Mosque. In the Tilla Kari Mosque and Madrasa, more than 120,000 cubic meters of top-soil were removed and existing underground services were displaced. This work led to the discovery of ancient pavements which were incorporated in the restoration project. Central Asian monuments are often touched, sometimes destroyed, by earthquakes, and the use of reinforced concrete concealed by brickwork has substantially increased the seismic resistance of the Registan Square Ensemble.