During work to the main drainage system of Canterbury in 1868 the city engineer, James Pilbrow, observed the foundations of the NE drum tower of St George's Gate beneath the modern surface.

From January to March 1933 the Corporation of Canterbury undertook work to replace the main drainage system from St George's Street to the Kings Bridge. The City Engineer, Mr H. M. Enderby, decided to follow the line of the old brick barrel drain built by Pilbrow in 1867-8.
One of the most interesting rediscoveries was the base and foundation of St George's Gate (c. 1450) and demolished 1801. From 0.53m below the road level the foundation extended down a further 2.44m, and from the section uncovered, it appeared that the circular base was between 6.10m and 9.14m in diameter. The mass was faced in Ashlar masonry with a flint core. The Canterbury Archaeological Society secured some interesting photographs before the base was covered in.

In February 1988 Canterbury Archaeological Trust excavated on the site of St George's Gate (Newingate), prior to a series of road improvements. The site code was STRG88 and the excavations lasted 6 weeks, in two three weeks phases.
St George's Gate was not a Roman structure and was constructed by breaching the city wall, possibly as early as the late 9th/early 10th century. Sections of the Roman wall and rampart, built AD 270-90 , were seen during the excavation, buried under later work. Mortar debris, sandwiched between layers of dumped clay and soil, was evident in the rampart mass, indicating that wall and rampart construction were carried out simultaneously. Sealed beneath the rampart was a Roman topsoil, bearing traces of the plough.
Traces of an earlier gate were also found within the excavation, including opposing greensand quions placed on either side of the opening, under the carriageway at the front of the late gate. These had been used as footings for the replacement gate.
The presence of large pits, cutting the Roman wall, berm and inner edge of the defensive ditch south of the gate, indicated that by the late 12th century this part of the city's defences was in considerable disrepair. Large quantities of iron working slag removed from the pits and adjacent ditch fills also suggest industrial activity outside the city walls at this time. Documentary sources indicate that repairs were undertaken c. 1483 at St George's Gate. It is thought that the earlier structure was actually Medieval rather than Anglo-Saxon, suggesting the walls were not breached at the earlier date of 9-10th century.
The surviving fabric of the gate consisted of ashlar skirts of Kentish ragstone, for both towers and still bore quarry tally marks. The massive gate towers of chalk block-work faced in flint and stone, flanked a narrow carriageway barely 2.29m wide, which was carried over the city ditch on a wooden drawbridge. Patches of road metalling survived between the supporting walls for the gate opening and carriageway vault. The style of the gate appears to have been modelled on that of the Westgate, distinctly military and conservative. There was a portcullis protecting a two-leaf doorway. Above the gateway and three trefoil-headed niches and panels were machicolations. Access to the upper floors of the drum towers and gun loops was by a spiral stair set behind the southern drum tower. The foundation of this stair turret was uncovered during the excavation.
The gate was eventually demolished, due to commercial pressure, in 1801. (6-11)

Description from record TR 15 NE 76:
[TR 15165761] St George's Gate [NR] (Site of) [NAT]. (1) Newin or St George's Gate built c1467. (2) Demolished 1801-2. (3) Part of the north-east drum tower of St George's Gate was located during drainage operations. (4) St George's or Newingate was the only major gate in Canterbury not of Roman origin. It was first built in the late 9thc or early 10thc after a gap had been made in the Roman city wall at the end of the new High Street. From then until its demolition in 1801 it was, with the Westgate, one of the two most important gates in the city wall. It is first documented in a Canterbury Cathedral Charter of c1100. It was repaired between 1469-70 (See illustration card). (5)

<1> OS 1:2500 (OS Card Reference). SKE48196.

<2> Arch J 86 1930 243 270-8 (G Home) (OS Card Reference). SKE36731.

<3> Canterbury in Olden Times 119 (Brent) (OS Card Reference). SKE38543.

<4> Arch 43 1871 pl XXII 16 152 (Pilbrow) (OS Card Reference). SKE34419.

<5> Cant Arch 1987-88 17-23 (P Bennett M Houliston and T Tatton-Brown) (OS Card Reference). SKE38487.

<6> Mead, H. T., 1934, Discoveries during the Main Drainage Works, High Street, Canterbury. January - March, 1933. (Serial). SKE29759.

<7> Andrews, G., 1985, An Assessment. Gazetteer of Excavations. Prehistoric, Belgic and Roman Excavations (Monograph). SKE30006.

<8> Pilbrow, J., 1871, Discoveries made during excavations at Canterbury in 1868 (Serial). SKE30226.

<9> Bennett, P. & Houliston, M., 1989, St George's Gate (Artifact). SKE30634.

<10> Williams, A., 1947, Canterbury Excavations: September-October 1944 (Article in serial). SKE30786.

<11> Canterbury Archaeological Trust, 1989, CAT Annual Report (Monograph). SKE30887.