The cache is NOT at posted coordinates! But is somewhere nearby....
The posted coordinates are however at a convinient bus stop for getting here (the 24 bus runs close to the southern end of the adventure lab trail, while the 33, 49 and 51 run from nearer its northern end).
Edinburgh's Historic Hospitals Adventure Lab has taken you past some of Edinburgh's hospitals from days gone by, this bonus cache is a little further out near Little France and the current site of The Royal Edinburgh Infirmary, where medical care continues to evolve. The first patients were treated here in January 2002, and the move from Lauriston was completed in 2003. The site now holds various companies, the Chancellor's Building (part of the University of Edinburgh Medical School), the Queen's Medical Research Institute (which also houses part of the Edinburgh Imaging Facility), the Centre for Regenerative Medicine and the Sick Kids Hospital.
To get the coordinates for this, you have to complete the Adventure Lab Cache "Edinburgh's Historic Hospitals" which is a few miles north of here. The journal entries for the Adventure Lab will give you five numbers A-D, to get the actual cache location pop the numbers into the formula:
N55 5A.DE(B+C) W003 0(C*D).CDB
When retrieving the cache please be careful and keep to the paths, there is not a pavement down Craigmillar Castle Road and you do not need to walk down it. You may need tweezers to extract the log from its inner container (please return it there to keep it drier) but the cache has space for small swaps and trackables.