CIMRM Supplement - Mithraeum II. Köln, Germany.
The following photographs were taken by Carole Raddato at the museum in Köln in 2014. It is not quite clear whether they belong to Mithraeum 1 or Mithraeum 2. She says,"Birth of Mithras, votive inscription altars and tauroctony are from Mithraeum near Cathedral [i.e. Mithraeum 2] - Vessels from Zeughausstrasse".
R.L. Gordon writes that a Mithraeum was found in 1969 beside the cathedral, but is "of small importance". It was built in the cellar of a private house near other substantial houses of the second half of the 2nd century AD. The only inscription (#23) is by a veteran, legion unknown.
G. Ristow, Mithras im römischen Köln (Études préliminaires aux religions orientates dans l'Empire remain, 42). Leiden: E. J. Brill, 1974. Pp. 33, frontispiece and 23 plates. DFl 36. Also contains more information on Mithraeum I (CIMRM 1018) than previously available.
Reviewed: R.L. Gordon, Journal of Roman Studies 65 (1975), 247. Online here.
See also discussion here in ANRW II p.2038 by Roger Beck.
This mentions a vase with Sol flanked by the torchbearers.
Coordinates: 50° 57' 00" N, 6° 58' 00" E / 50.950° N, 6.967° E.