Pompeii

One of the surviving murals. They would paint wall-width murals of scenic pictures. The idea was to make the interior courtyards feel as if there were large windows looking out onto the countryside.

Some of the ruins of Pompeii

The city of Pompeii was based on an "open" sewer system. The stepping stones were used for safe passage across.
When Vesuvius exploded, Pliny the younger described that the volcanic cloud looked like an umbrella pine. We would have said that it looked like a mushroom cloud.

Vesuvius in the Sunrise
(Of course I got a picture of the volcano!)