Info dumping is putting in too much information that bogs down the story. How much is too much depends on a lot of factors, including writing style and genre and PoV.
As was customary in the Holy Roman Empire in the late first century BC, the courtyard was surrounded by Roman cement, made from the ash of Mount Vessuvius, and plastered white. The tops were.
Info dumping, here, means giving details I, as a reader, have no reason to possibly care about. Do I care if that was customary? Or that it was customary just in that century? No, not in the least. Now, same scene, more showy about how the character's eyes take in their surroundings.
The garden was perhaps sparse, but the walls gave her the sense of privacy she often found lacking in the rest of the settlement. Honestly, father should know better than to drag his daughter out into his campaigning.
Still. Though the barracks was lacklustre compared to the grandeur of Rome, little comforts like the arches and the familiar Roman architecture helped anchor her in her Roman identity, as opposed to... wherever she now finds herself.
Barbarians, those Gauls. Though that was no concern of hers.
Through showing, the astute reader could perhaps pin an era to the scene. Why drop in years and dates, that isn't how people tend to think. Not unless they are keeping a Captain's Log (insert date in your best Kirk voice). Maybe you could have women gossiping about the latest goings-on in Rome, famous events, assassinations, stuff that those who know about the time period know about and can date for themselves. Dating it is telling, speaking of the event is showing. Which works, depends entirely on how you mean to portray the scene.
Now let's compare what a general of the Roman Legions might notice?
He didn't salute the soldiers standing at attention, nor did he care to. The saluted him, that was enough. Their armor wasn't polished, though--he'd have to speak to his future son-in-law about the ragtag fools that would soon be guarding his daughter.
Strolling through the arch, he ignored the servants going about their business. Up the three stone stairs, and through the wooden door. Into the sitting room, ignoring the seating and the lace foolishness he never cared for.
"Brutus! We must speak!" he bellowed, his words reverberating through the stone walls. No matter the fancy whitewashing or whatever fluff they used, stone was unforgiving, be it to voices that echoed off it, or someone's face being smashed into it.
What he notices is telling for his character. How he describes it even more so. If you put a historian that has wet dreams about that era in that room, he'd do what any historian would do: gush about all the details, and likely info dump the heck out of it. But a man who's more concerned with training men and wielding the Roman Battalion under his command as if a sword? He won't care much about the frills, as is evident in the scene, no?