Decumanus maximus is a big and important street in ancient Roman cities that ran from east to west. It was like the main avenue or highway in a city, and it was used by people to travel from place to place.
In simpler terms, think of it as a super-long road that was really important for the Romans living in their cities. It was like the main street of a town, but on a much bigger scale.
Many important buildings were located along the decumanus maximus, including temples, government buildings, and markets. This street was the center of activity in a Roman town and was essential to the life and growth of the city.
So, if you were a little Roman living in a city and wanted to go to the market or go see the temple, you would probably walk along the decumanus maximus to get there. It was a pretty big deal!