The Ohrid Paleo-Christian Baptistery
Plaošnik Basilica, Ohrid, North Macedonia
Various sources date the baptistery, and thus its mosaics, as 4th, 5th, or 4th-6th century.
See my page on the Fountain/Kantharos Symbol Paradigm for a full discussion.
The above image in full resolution
Below is a photo of the mosaic in context. It is on one long side of the font. The mosaic on the other side has the same two pairs of creatures approaching the same fountain, but the two rivers are the Tigris (not seen in the photo) and the Euphrates (lower right corner of the photo). Jensen, Baptismal Imagery, suggests that this font shape appears "to have been designed to represent a woman's vulva.… These fonts' undulating and elongated shape allowed for entrance at one (probably the western) end, passage through the water, and emergence on the other side" (165).
First photo © by Jan Piebe Tjepkema.
Second photo: Diego Delso, delso.photo via Wikimedia Commons, license CC-BY-SA.