One of the most striking features of the medieval church of San Clemente in Rome is the semi-dome of its apse. Covered in golden mosaics from around 1200, a cloud of circular, swirling tendrils frame a unique crucifix adorned with doves. If the designs look familiar to you, they have interesting cousins, including 7th century precursors in the Byzantine-inspired mosaics on the interior of the Muslim Dome of the Rock in Jerusalem, as well as some later manifestations in the work of Gustav Klimt, especially in his painting The Tree of Life of 1905.