CAER-SWS, a hamlet, in the parish of LLANWNNOG, hundred of LLANIDLOES, county of MONTGOMERY, NORTH WALES, 5 miles (W.) from
Newtown. The population is returned with the parish. This is said to have been a Roman city of considerable extent, though
unnoticed as such by early writers: its Roman name is not even known, and few vestiges of its grandeur have been traced.
In Mr. Pennant's time the fields in the vicinity were divided by lanes intersecting each other, which probably pointed out
the places that had formed the ancient streets, but the exact size of the station is not known. A Roman road, called Sara
Swsan, or &nog, led from it in a direction northward, though whither it proceeded is doubtful, and but little of it can
now be discovered. By the side of this road, on GwSrnvynydd common, there is a small sub-oval encampment; and in a field
adjacent to Rhos Ddiarbed, " the common where no quarter was given," is another Roman camp, of singular form. At the south
side there is a vast conical mount, surrounded by a deep fosse, supposed to have been exploratory, to the north of which
an oblong area, about seventy yards broad in the greatest diameter, is defended by 'a high rampart and outer ditch: in
the lower part there is an entrance to a square camp, about two hundred yards in length, and above one hundred in breadth,
opposite to which is another entrance: the whole is surrounded by a rampart and ditch. No coins have been discovered
here, but, about the year 1777, some Roman bricks, and large blocks of cement, much indurated, and as porous as breccia,
were dug up in the south-western angle of the camp: one of the bricks bore an inscription in bas relief, which has not
been satisfactorily decyphered, and was placed in the back part of a chimney belonging to the apartment of an adjoining
inn. Caer-Sws had formerly a castle also, and at least one church, and is said to have been the residence of the lords of
Arwystli. It is situated on the northern bank of the river Severn, across which a new stone bridge of three arches was
built a few years ago, and has been enlarged, within the last fifty years, by the erection of some decent houses and
cottages: a new road, leading from Caer-Sws to Llanwnnog, was constructed in 1831. There are places of worship for
Baptists and Calvinistic and Wesleyan Methodists.