Very near to the cathedral on the south-west is the now much more interesting baptistery. This is on the exterior a large and lofty octangular building, adorned in a succession of stages by small detached shafts carrying the cornices and strings which divide the elevation. Internally the scheme is very different. The eight-sided interior is subdivided, so that sixteen shallow apses are set around the inside face of the walls. These are separated by columns, and above them on each side are two stages in height, each subdivided into three divisions, which are again subdivided by smaller columns. A great vault or cupola covers the whole, and from its height gives an air of solemnity to the interior. It seems never to have been treated as a real dome, being covered with a flat roof, resting on the external walls, which are carried up far above the vault. The paintings with which the walls are covered are arranged without any order or general scheme of design. They seem to have been given by various donors, and each gave what best pleased his fancy; but owing to the early date of most of the work, there is in parts—especially in the vault—a fine effect of colour.
