GROTTO HILL 1 1380 The Grotto TR 3570 NE 6/169 I 2. Many theories have been advanced for the origin of the Margate Grotto, including Phoenician origin or a Roman Mithraic Temple. The Grotto was discovered in 1835 by a schoolmaster and his sons digging their back garden. It is however most likely to be early C19 as there are traces of a modern brick in one of the Gothic shaped arches. The pattern of the Grotto is 2 semicircular passages leading to a central dome and then a passage leading off to a rectangular chamber. The Grotto has about 2000 square yards of shell mosaic consisting of 28 different types of shells, many of which are foreign. The cement which adheres the shells to the chalk walls is very similar to Roman cement and is said to contain fish oil and crushed shells. The motifs include common Egyptian, Greek and Indian motifs. In the rectangular chamber are motifs of the rising sun, the moon and stars. The modern buildings at ground level are not listable. Listing NGR: TR3593270870