In 1835 a labourer was digging a field near the English seaside town of Margate when suddenly his spade vanished into the ground. A young boy was lowered into the void via a length of rope to see where the spade might have gone. When the boy was pulled back up he reported an amazing discovery: a temple adorned with of shells, 4.6 million of them!
When was this underground wonder built and why? There has been much conjecture over the years. Mick Twyman of the Margate Historical Society suggests that the grotto may have been built by the Knights Templar or their associates sometime in the middle 1100s. But no one knows for sure.
(Details on visiting the Grotto here.)