Aquilea was a Roman city since 180 BC, and a major centre of trade and crafts including beautiful blown glass.
At its height it had a population of around 100,000. It declined with the barbarian invasions in the5th Century. It's still being excavated today.
But in the 4th Century a basilica was built, after the edict of Milan, which put an end to the religious persecution of theChristian community. The floor of thebasilica was decorated with with a wonderful coloured mosaic, the largest existing Paleo-Christian mosaic in the world. Here's a photo to give you some idea of the size. This is only a small part of the floor.
Hundreds of years later, in 1031 another floor of red and white marble was laid over top, thus preserving the work. it was removed in 1910 to reveal these precious and amazing mosaics with symbolic scenes depicting the origins of Christianity in Aquilea. The mosaics also include many pre-christian symbols. I don't know much about the history of Christianity in ancient Rome, but I was so impressed with the artistic quality of these mosaics, which have many naturalistic animals, birds and fish as well as decorative elements.
And here you can see food: a bowl of mushrooms, a plate of snails. It gives such a sense of how people lived over 2000 years ago.