While enjoying a coffee nearby, we noticed the name of a lane - Barracks Lane and wondered if it was the location of the original soldier's barracks, or maybe the prisoner's barracks - which one could it be?
This location was the site of the temporary Prisoner's Barracks which was built soon after the settlement was established in April 1821 (see building No. 10 in the image below). There was a vegetable garden adjacent to it as they had to be self sufficient as soon as possible. By 1828 Port Macquarie as a penal settlement was virtually a prison without walls. By 1831 the original Prisoner's Barracks were being used as a boat shed and a new Prisoner's Barracks was built on the escarpment between Allman's Hill and Government House. This was later converted to an asylum for the invalid.
The Cache
You are looking for a magnetically attached "container" which the cache "Size" listed should give you an idea of what it is. You will have to be nimble to sight the container and grab it without being seen as this is a high muggle area.
Abg va, ohg haqre.