Yes it was lovely in the age of musket and white arsenic powder! Alas it is NOT lovely at all in the age of white togas!
Castra
The Romans did build castras when they are not fighting and marching, they built a square walled city of palisades with dry moat and spikes pointed outwards. But it was "BuildForNightAndTearItOnMorrow" doctrine in force! The castra gave the legion protection from ambush and various pos factors i.e. better infrastructure, but it cannot fall in the hands of those wildings so they teared the camp already the day before they moved on!
This picture shows how they built the castra - always had four gates in case of dangerous situations!
When the legions were in enemy lands they built castra
every night and
teared it down by morrow!! it shows the amazing military engineering and hard discipline among the legionnaires!
They also used garrisoned forts or sentries along borders to protect from raids or warpaths! But those were mostly manned by auxiliary forces and the legions used them as logistic bases, as great
Vegetius explained!
So there should not be permanent forts, only alongside the borders! If according to history!
But, yes the temporary forts should have area of interception as legions sent scouts by day and night!
Sources -
Castra