Baked

This is a fragment of a Roman tubi fittili made from clay baked in the sun; my entry for today's MonoMonday challenge on the theme "baked". I found it in Tunisia.

Vaulting tubes (tubi fittili) are hollow terracotta tubes which were employed in Roman architecture to construct a lightweight framework for a vault, an arched structure which formed the ceiling of a room. Vaulting tubes were used primarily between the 2nd and 7th centuries C.E., often in the construction of bathhouses and major churches throughout the Roman Empire. They are found predominantly in North Africa, though examples have also been found in Sicily, Italy, Spain and Britain, as well as in shipwrecks throughout the Mediterranean.