The Romans did not invent drainage, sewers, the alphabet or roads, but they did develop them. They did invent underfloor heating, concrete and the calendar that our modern calendar is based on. Concrete played an important part in Roman building, helping them construct structures like aqueducts that included arches.
This could link to study of the inventions listed. Students could discuss the difference between inventions and discoveries. Students could look into arches, domes and other structures that the Romans built.