<prompt> Translate the following text to EnglishKatika sehemu ya mwisho ya nave ya kulia ni baptistery ya karne ya tano, moja ya majengo ya kale zaidi inayojulikana katika Ulaya ya Kikristo na baadhi ya mosaics ya awali bado intact.  <response>: At the end of the right nave is the fifth-century domed baptistery, one of the oldest buildings known in Christian Europe with some original mosaics still intact. 