The entire site was relocated to permit continued construction and this temple of the mystery god Mithras became perhaps the most famous 20th-century Roman discovery in London.

[1] The temple, initially hoped to have been an early Christian church, was built in the mid-3rd century[a] and dedicated to Mithras or perhaps jointly to several deities popular among Roman soldiers.

Found within the temple, where they had been carefully buried at the time of its rededication, were finely detailed third-century white marble likenesses of Minerva, Mercury the guide of the souls of the dead, and the syncretic gods Mithras and Serapis, imported from Italy.

On it Mithras is accompanied by the two small figures of the torch-bearing celestial twins of Light and Darkness, Cautes and Cautopates, within the cosmic annual wheel of the zodiac.

The varied objects are thought to have been brought to the site in landfills and soils collected elsewhere and laid down to improve the marshy banks of the River Walbrook during the rebuilding of London after the Boudican revolt of AD 60 or 61.

[9] The local waterlogged soil conditions then preserved even organic material like leather shoes[10] and a large assembly of wooden writing tablets of which over 400 were found.

Nearby, in its former streambed, a small square hammered lead sheet was found, on which an enemy of someone named Martia Martina had inscribed her name backwards and thrown the token into the stream, in a traditional Celtic way of reaching the gods that has preserved metal tokens in rivers throughout Celtic Europe, from the swords at La Tène to Roman times (compare wishing well.)

[20] The Walbrook Square project was purchased by the Bloomberg company in 2010, which decided to restore the Mithraeum to its original site as part of their new European headquarters.