The Romans had two types of camps they built. One was a more permanent camp they used for occupation and defending borders. This would be a more elaborate camp with better defensive structures and permanent housing. Then there was the Roman temporary camp they built on campaign. It was built on the go and would be their housing for typically a night or two.

It sounds like the video you watched was about the temporary camps. The temporary camps were very unique and gave them a good advantage. It wasn’t for their impressive defensive structures and defenses though. Most civilizations are capable of building impressive forts. It was for their ability to build them in just a matter of hours.

The Roman legions, post Marian onwards, could spend the day marching, stop and build their camp. Rest for the night in relative safety, then tear down the camp in the morning and go on. In some cases, like Gaius Julius Caesar recounts from his time in Gaul, they would be attacked during construction of the camp. They would still get the walls of the camp up during the battle. That was their advantage and what made their camps unique over every one else at the time. There was no opportunity for an enemy army to catch the Romans with their pants down. They built a mini fort every time they rested for the night.

What helped them be able to do this was their standardized layout. They were either rectangular or square. Square for one legion, rectangular for two. On the outside there was a ditch, to a standardized depth. Then there was a rampart that lead to the edge of the pit. Also a standardized height. At the top of the rampart was wooden spikes. Each soldier would carry one of these, and take them with them when they left.

Then there was the wooden wall. The wall had four entrances, and these temporary camps often didn’t have any sort of gates at the entrances as well. Just a rampart that forced them to funnel into the entrance. Four roads came from these entrances and intersected near the middle. They did that for easy access and and to move their troops around easily.

Behind the walls was a standardized distance before any of the tents. This was to help prevent the tents from being hit by flaming enemy projectiles. The General’s tent was always in the middle. Why? Well the general, or legate, could easily give orders to all parts of the camp. With the higher officer’s and centurion tents around it. This was for them to have easy access to the general and to be able to easily get together and plan. The calvary and infantry then made up the outer tents. The infantry slept 8 men to a tent.

This standardized layout helped them build their camps efficiently. Every time it was the same. It could be built in hours in the heat of battle. That was what was so special about it. You couldn’t catch a Roman army napping. As for the four quadrants part, I’ve never heard a reference to that.