This weekend I got around to visiting the Roman Baths at yes, you mebbe guessed it, Bath - the largest building in Roman times had a 15 metre columned portico with a pediment frieze of elaborate bas relief. One of the details still extant is a picture of the world which the learnéd hi cara commentary stated unequivocally represented a Roman world view of a spherical earth.

I have a digital pic if anyone's interested further.