This insula lies due north of the clinic site, and coincides with most of the Hollytrees Meadow. Internal detail is quite well known. The principal building is the L-shaped structure which now lies under the east side of the children's playground (Fig 1 'Roman building'). This has been known since 1853 when it was first discovered by P M Duncan, who thought it was a bath-house because of its concrete floor and the water running through it. It was partly excavated in 1927 (Hull 19582, 107-113) and again in 1954 (Crummy 19803, 271). Although there was no direct evidence in the form of inscription or statuary, Hull was in favour of interpreting it as a carcer (prison) because of its sunken floor and the slave chains found in it. However, he decided to interpret it as a building of ritual or religious use - a temple of the eastern god Mithras (ie a mithraeum). Nowadays, archaeologists are less confident on interpretative issues, and a more prosaic use for this building (a ?waterworks) is now accepted. Oddly enough, the building is surrounded by a wall, double on its south and east sides, which would be more normal in a structure which had some special significance.
A drain emerges from the building and runs along the road edge and north through Duncan's Gate (also discovered by P M Duncan), after which it drains into the Roman ditch outside the wall. It is still possible to peer down into the drain through two metal grilles, near the children's playground and near Duncan's Gate.
From the 1920s excavations and a watching brief in 1984 (CAR 6, 368-73), we know that there were extensive buildings on the north and west sides of the insula, including a very interesting-looking small building immediately to the west of the old
mithraeum (it now lies directly under the children's playground). It is not known if this was a temple or a shrine.
With regard to the depth of surviving remains (below modern ground-level), the south wall of the mithraeum is only 20cm below modern ground-level, and the north south street separating Insulas 7/8 and Insulas 15/23 shows as a parch-mark in dry weather, indicating that it lies very close to the surface.
Remnants of a Mithraeum, discovered for a second time (1929) East of the
temple dedicated to Claudius. Formerly (1853) explained as a water-basin.
Hull in ILN 24 May, 1930, 936 with plan and reconstruction. I am very grateful to Dr M. R. Hull, Curator of the Colchester and Essex Museum, who was so kind to explain me the terrain and to give me perusal of his still unpublished reports. See fig. 222.
New excavations have made it possible to draw up a ground-plan. The underground sanctuary A is preceded by a higher (2.00), overground room D, a pseudo-porticus accessible on the E.-side by an entrance. Along a narrow corridor, past several apartments one arrives at another entrance (Br. 1.43), which leads to a flight of stairs, which give access to the actual sanctuary. This is enclosed by heavy (1.00) brick walls, parts of which are still erect on the S.-side.
The room, which is twice as long as broad (L. 13.00 Br. 6.50) is divided into three parts: the central aisle: in which still footsteps are visible, and the two sidebenches with elevations against the backwall. These were made of wood as is clear from traces of wooden beams, which are visible in the small gutters (Br. 0.25 D.0.20), which were made in the floor on a distance of 1.57 from the walls.
Near the N.-wall, approximately in the middle, an isosceles triangle has been
hewn out (base 0.42; sides 0.30). Under the stairs is a well, of which the richly
flowing water is checked by a small dam. But sufficient water passes through it
to fill a square cement pit (Br. 1.00 D. 0.66) in front of the well. Excess water is
lead away through a square hole (Br. 0.22) in the N.W.-corner. This communicates
with the sewerage of the town.
No cult-objects have been preserved, but the room was full of pottery for the
greater part refuse from the fourth cent., which judging from its position must
have been thrown over the walls.
Of the few entire pieces, we mention only a sieve of grey material. Moreover a
skeleton was found.
The exact date is hard to define. The coins date from Trajanus to Valens or
Valentinianus. Numerous are the coins of the Tetrici (about 270), whereas a coin
of Constans as Augustus, found in the under layer, may point to the possibility,
that the Mithraeum was still in use in the period of 337-350. The date of building
is rather early, accordiug to the other coins. The walls however, date from the same
time as the rampart, the date of which is most probably the second cent. according
to Hull. But this is a vexed question.
R.G.Collingwood, The archaeology of Roman Britain, p.145, n.1: "The building at Colchester described as a Mithraeum in the Illustrated London News, May 24, 1930, is in the present writer's opinion a water-tank."