The Margate Shell Grotto, a winding underground passageway in Kent, England, decorated with nearly 4.6 million seashells, is one of the greatest unsolved mysteries in the world.
Legend has it that in 1835, James Newlove and his son, Joshua, were digging a duck pond in Margate, Kent, when they noticed a hole in the ground. Newlove then lowered his kid down there to check it out, according to BuzzFeed.
The hole turned out to be caverns connected together by several underground tunnels with walls covered in intricate mosaics made out of millions of seashells (video below).
The shells in the grotto include scallops, mussels, limpets, whelks, cockles, and oysters, all of which can be found locally. In all, there are more than 2,000 square feet of shell mosaic in the grotto, according to Viral Nova.
Once the hole was widened by the locals, they found that the various underground tunnels also had a rotunda, and an altar chamber with every square inch decorated in shells. A rotunda is a building with a circular ground plan.
Newlove, a school teacher, ended up acquiring the land where the shell caverns were located, and after years of renovation, he opened it up to the public as the Margate Shell Grotto.
While there is no doubt that the decorated caverns are beautiful, no one actually knows who built the grotto or why.
Some claim it has religious significance and could have been built more than 3,000 years ago, Mad World News reports. Others believe it is connected with the Freemasons or Knights Templar.
The grotto’s age could be determined using carbon dating, but that method is very expensive and conservation issues would adversely affect the shells.
No matter who originally built these caves, it is a beautiful example of historic artwork.
Check out a video of the grotto below: