Mausoleum of Galla Placidia in Ravenna

You're standing at the Mausoleum of Galla Placidia in Ravenna. From the outside it may not look like much. A plain little building of red brick in the shape of a cross, with a square tower in the middle. The only decoration is the row of blind arches running around the walls. It looks as if the building has sunk into the ground a bit. That's because the ground around it has risen over the centuries.