Hassan Tower

Begun in 1195 by the Almohad caliph Yacoub al-Mansour, the Hassan Tower was intended to be the world's tallest minaret, the centerpiece of the largest mosque in the western Islamic world. Al-Mansour died in 1199 and construction stopped at 44 meters — less than half the planned height. The mosque's 348 columns still stand in rows across the plateau, a forest of stone that was never roofed. The 1755 Lisbon earthquake destroyed much of the prayer hall. Today the tower stands opposite the Mausoleum of Mohammed V, its incompleteness making it more powerful than completion ever could.