The citizens of North Leith buried their dead in St Nicholas' Churchyard, until it was destroyed by Cromwell in the mid-17th century. To compensate them, the city gave them this small piece of ground between the Water of Leith and what is today Coburg Street.  

Above is the altar-tomb of Thomas Gladstone, grandfather of William Ewart Gladstone who became Liberal Prime Minister in 1868.

I'd previously assumed this tomb was being used by one of the city's homeless, but on a return visit found saucers of cat food !

The inscription on top of the monument reads :

Sacred to the memory of Evan Liddell,
Merchant in Leith,
Who died 29th August 1830, aged 56 years.
And of his wife Agnes Brown,
Daughter of Edward Brown, Harbour Master, Leith,
Who died 20th May 1811, aged 33 years.
And of Mary, their youngest daughter,
Who died 21st August 1840, aged 29 years.
All interred beneath this stone.
And of Agnes, their fourth daughter,
Wife of the Rev. William Stevenson,
Who died 20th September 1841, aged 31
Interred North Mavine, Shetland.

And finally, a winged soul marks the grave of John Broun, Ship Master in Leith who departed this world on the 16th October 1744, aged 60.