Hassan Tower

Hassan Tower or Tour Hassan (in French) is the minaret of an incomplete mosque in Rabat, Morocco. It was commissioned by Abu Yusuf Yaqub al-Mansur, the third caliph of the Almohad Caliphate, near the end of the 12th century. The tower was intended to be the largest minaret in the world, and the mosque, if completed, would have been the largest in the western Muslim world. When al-Mansur died in 1199, construction on the mosque stopped. The minaret was left standing at a height of 44 meters. The rest of the mosque was also left incomplete, with only the beginnings of several walls and 348 columns being constructed. The tower, along with the remains of the mosque and the modern Mausoleum of Mohammed V, forms an important historical and tourist complex in Rabat.

Building data from Wikidata (CC0); heights normalised. Summary from Wikipedia (CC BY-SA).