Roman Caerleon

Caerleon is a site of considerable archaeological importance, being
the site of a Roman legionary fortress (it was the headquarters for
Legio II Augusta from about 75 to 300 AD) and an iron age hill
fort.
The name Caerleon is commonly thought to be from the Welsh for
"fortress of the legion"; the Romans themselves called it Isca
Silurum, "Usk of the Silures", after the Silures, the Celtic tribe
that dwelt there.
Substantial excavated Roman remains can be seen, including the
military amphitheatre, one of the most impressive in Britain,
barracks and defensive formations, and the bath house, with a
modern museum in situ above it. Both sites are administered by
Cadw. There is a separate museum, part of the National Museums and
Galleries of Wales complex, which exhibits finds from excavations
throughout the village.
Because of its circular form, the unexcavated amphitheatre was
known to locals as "King Arthur's Round Table". An initial
investigation in 1909 showed the potential for a full-scale
excavation of the structure, which began in 1926 and was supervised
by Victor Nash-Williams. This revealed, among other things, that
the amphitheatre had been built around 90AD, but had twice been
partially reconstructed, once in the early part of the 2nd century
AD, and again about a hundred years later. The arena is oval in
shape, with eight entrances, and the stadium is thought to have had
a capacity of around 6000.
Caerleon and Arthurian Legend
Caerleon is one of the sites most often connected with King
Arthur's Camelot. There was no Camelot mentioned in the early
Arthurian traditions recorded by Geoffrey of Monmouth, Wace, and
Layamon. These early Arthurian authors say that Arthur's capital
was in Caerleon, and even the later recaster of Arthurian material,
Sir Thomas Malory, has Arthur re-crowned at "Carlion" (Caerleon).
It has been suggested that the still-visible Roman amphitheatre at
Caerleon is the source of the 'Round-Table' element of the tales,
and was used for discussion and entertainment. (The "Camelot"
reference originates with the French writer of courtly romance,
Chrétien de Troyes.)
Geoffrey of Monmouth writes of Caerleon in the mid 12th
century:
"For it was located in a delightful spot in Glamorgan, on the River
Usk, not far from the Severn Sea. Abounding in wealth more than
other cities, it was suited for such a ceremony. For the noble
river I have named flows along it on one side, upon which the kings
and princes who would be coming from overseas could be carried by
ship. But on the other side, protected by meadow and woods, it was
remarkable for royal palaces, so that it imitated Rome in the
golden roofs of its buildings... Famous for so many pleasant
features, Caerleon was made ready for the announced feast."
(Historia Regum Britanniae "History of the Kings of Britain")
Caerleon also has later Arthurian literary associations, as the
birthplace of the writer Arthur Machen who often used it as a
location in his work. Alfred Lord Tennyson also wrote his Idylls of
the King overlooking the Usk in a bay window of what is now the
saloon bar of the Hanbury Arms public house.
In Michael Morurgo's novel Arthur, High King if Britain, Caerleon
is the castle where Arthur unknowingly commits incest with his
half-sister Margause, resulting in the conception of his bastard
son Mordred, who will later bring about his downfall.
The Barracks
A paranomic view of the barracks:

A close up of the defensive formations, showing the ramparts with
the trench on the other side, and gaps where entrances to the
fortified barracks would have been:

The fort from the "outside", showing the defensive trench in front
of the defensive ramparts.

The Amphitheatre

A paranomic view of the amphitheatre:
