The cache is NOT at the posted coordinates, but its not far away, near Greyfriar's Kirkyard. If you do go to the posted coordinates, you will be standing between 2 great institutions that have historical links to slavery: the former buildings of the Royal Infirmary of Edinburgh on one side of the road, and on the other side, George Heriot's School.
This is a BONUS physical cache to reward you for completing 2 adventure labs: Edinburgh's Roots in Slavery, part 1, and Edinburgh's Roots in Slavery, part 2. Each of them contains 3 clues to help you find the coordinates for this bonus hide. Once you have all 6, you can find the cache.
The hiding place is at:
N55 56.ABC W003 11.DEF

You may be surprised to learn that Greyfriar's Kirkyard, which is best known for the grave of the faithful wee dog Greyfriar's Bobby, and also the grave of Tom Riddell, inspiration for JK Rowling's character Voldemort in the Harry Potter stories, also has an indirect link to slavery, of a different kind to that you have learnt about in the adlabs. The slavery that Edinburgh landowners were involved in was mostly about innocent negroes who were taken from the West coast of Africa, transported across the Atlantic and sold to owners who exploited, dehumanised them, worked them hard in the plantations, and regarded them as their own belongings to be bought and sold and left to their descendants in their wills.
This bonus cache is concerning the use of slavery as a punishment for a crime; in this case, Scots living free in Scotland, who commited a crime that led to them being transported to those same colonies and into the plantations where they were sold into indentured servitude and also treated as slaves. They were covenanters.
There is no doubt that there are illustrious people interred here who were involved in the slave trade back in their day. The names Charles Stewart (customs official), George Watson (hospital and school founder), William Wright (botanist and surgeon), Walter McFarlane (land owner) to name but a few.
However, there is also a section within the kirkyard, known to this day as the Covenanter's Prison, now locked shut, that was used in 1679 to hold prisoners following the Battle of Bothwell Bridge. There were 1200 prisoners, too many for the available prisons, so about 400 of them were held here. The sick ones were held at Heriot's Hospital (now a school) nearby.
What was their crime? These prisoners were covenanters who had resisted the imposition of religious rule by the Church of England and the Episcopalian Church, defying King Charles II's 'Solemn League and Covenant', which attempted to get rid of Scotland's presbyterian churches. Defying the King in this way was considered to be treason. Some were executed, others sentenced to transportation.
The prisoners were held in terrible conditons for about 5 months, cramped together on the ground, with no shelter and very little food and water. Local people would sometimes throw food to them. Eventually, after trials took place, 275 of them were sentenced to transportation to the colonies, to be more exact, they were banished into indentured bondage in what amounted to slavery in the sugar plantations, or the tobacco fields in Virginia. Usually, these sentences were for a fixed period of time, at the end of which the prisoner would be set free with some food and money; but these covenanters were sentenced to life. Many of them never reached their destination due to the harsh conditions on the ships; perhaps they were the lucky ones?
Hopefully you have found the 2 adlabs interesting and discovered that Edinburgh has so many historical links to slavery.
The bonus cache should be possible to find from a wheelchair, but help may be needed to reach up to retrieve it.