Just to the north-east of the village of Braco and on the east side of the A822 lay the remains of Ardoch Roman Fort, considered by many to be among the most impressive forts anywhere in the Roman Empire. What you find on the ground is the traditional "playing card" outline, contained within a series of very well defined surrounding ditches and earth ramparts.
The outlines of the southern and eastern edges are relatively straightforward, but the northern half of the eastern ramparts have as many of six distinct lines of ditches and ramparts. The northern edge of the fort is still more complex, comprising eight or nine distinct lines of ditches and ramparts extending either side of what was once an access road. In addition there are very faint traces of the outline of a compound within the fort. These are all that remain of a medieval chapel.
The fort at Ardoch has survived so well largely thanks to the landowner in the late 1700s, Sir William Stirling. He enclosed the remains to prevent their being ploughed, a process that, as so often happened elsewhere, would have resulted in the ditches and ramparts being diminished in size or obliterated altogether.
In 1896-7 the Society of Antiquaries of Scotland excavated parts of the fort. They uncovered evidence of a complex sequence of development. The Romans first seem to have built a series of large marching camps in the area, perhaps during the initial campaign in northern Scotland by Julius Agricola in AD83. A fort was then established enclosing an area of about 2.5 hectares (6.2 acres). This would doubtless have helped support the line of Roman defences that ran north-east along the Gask Ridge, intended to protect the Roman area of occupation from the lands beyond. Within this first fort were a series of wooden buildings.
The Romans pulled back to what later became Hadrian's Wall in AD105, but returned to Scotland in AD139. The second fort at Ardoch seems to have been occupied in the decades either side of AD150. At 1.95 hectares (5 acres) it was smaller than the earlier fort, whose ramparts it partly incorporated and partly obliterated. This time the main buildings within the fort were erected in stone. In the surrounding area, faint traces can still be made out of a 25 hectare (62 acre) Roman marching camp, and of another covering an area of 52 hectares (128 acres).