This book describes the architectural restoration of the monumental Ghurid portal of the Friday Mosque of Herat, Afghanistan - a remnant of the original 12th-century architecture and decorative artwork of the Ghurids. The restoration took place under the auspices of UNESCO and the Afghan government in 1964, fifty years ago. The portal was also passionately preserved and redecorated by the Timurid rulers and artisans of Herat in the late 15th Century; this makes it unique among Ghurid monuments. Erik Hansen, A.W. Najimi and Claus Christensen, using photographs primarily by Kickan Hansen and field drawings by Erik Hansen, illustrate this book with historic and practical accounts of the architecture and restoration of this very important monument. This book also manifests the strong academic relationship of Danish scholars and conservation architects with Afghanistan society and monuments since the second half of the 20th century. The potential readership is envisioned to be students, architects, art historians and academics interested or engaged with the architectural conservation of historic Buildings in the Islamic World whether through research, restoration or teaching.