This is the forgotten Edinburgh tomb that has been shrouded in secrecy and buried beneath a picturesque hill.
Situated to the north of the City Observatory in the city, the burial chamber dates from 1795, and holds a secret.
It was only rediscovered and surveyed some 200 years later, prior to concealment after completion of drainage works.
The mausoleum is thought to be the first Jewish grave site in Edinburgh, and created by Herman Lyon, who was a wealthy Jewish man who arrived with his family in the capital from Prussia in 1788.
In 1791, Mr Lyon started looking for a burial plot for himself and his wife, as he said he did not want to be buried in a Christian site.
Therefore, he appealed to the Town Council to sell him land on Calton Hill.
And the plot of land atop the hill was sold to him for just £17 sterling.
Following a series of drainage works around the site in 2013, the Calton Hill mausoleum had its entrance concealed and was very quickly forgotten about.
And it did not appear on any city maps bar from one 1850s Ordnance Survey map. In fact, the description of the tomb implies it was originally a cave or fissure.
The Georgian tomb lay dormant and untouched for the best part of two centuries until two local men stumbled upon it after climbing through a rabbit hole and into the main chamber.
Then in August 2013, a full standing building survey was carried out by the AOC Archaeology Group, who identified the main chamber with its barrel-vaulted roof. The floor was covered in a deposit of modern hardcore, which experts presume was dumped there during the construction of the adjacent tarmac road.
The Lyon Mausoleum has been found to measure three metres by four metres, with a 12-metre-long passageway leading up to the crypt.
The entrance remains completely sealed off to the public.
However, if you're ever walking in the area, have a look out for a set of slabs around the north-western edge of the City Observatory. These are understood to be the roof of the burial chamber.
Very little is known about Mr Lyon or his wife, other than the fact that he made his money as a "corn operator" - which had nothing to do with farming. This archaic term was actually used to describe someone who worked in the field of chiropody.
Mr Lyon practised both as a chiropodist and dentist in the Canongate. It is believed he was successful in his career, given that he was able to fund a private mausoleum for himself and his family on such a prominent site.
