Basilica di Sant’Apollinare Nuovo in Ravenna, Italy
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Wikipedia. Here you can find panoramas of mosaics on the walls in full resolution (scroll down and click on the desired picture). Shot on the iPhone, processed and stitched in Lightroom and PTGui. All texts are readable! Upper parts of this panoramas is of lower resolution because of shooting from the bottom.

View from the entrance, Basilica di Sant'Apollinare Nuovo in Ravenna, Italy, 2019.05.09. Click on the picture to view full resolution panorama #
And here are the panoramas of the mosaics themselves, straightened! because immediately after stitching the upper part is very much curved. I shot several takes and they all stitches with the same waves, this is probably a roughness of the wall, but you almost can’t see it live by eye. Look at the sources: