The cache is not at the posted coordinates. See below for more information. The last 50 metres or so is off the path and the ground can be very boggy after rain. Best wear boots unless visiting after an extremely arid spell.
A Letterbox hybrid is a form of geocache which shares similarities with the Letterboxing hobby. The container holds a stamp which should stay in the geocache please. From a geocaching point of view there is also a standard logbook for you to sign. A Letterbox cache can act as other cache types such as a traditional or puzzle cache (it's the stamp rather then cache type that is important). On this occasion, this Letterbox is acting as a Multi.
The coords are hidden near a gate into the park at the posted coordinates. However, the coords are hidden in a special way, so we think that you will only be able to get them (along with the hint) after completing the nearby Let's Get Physical wherigo. The gate is less than 100 metres or so from from the final of the wherigo, so you will need to go past the starting point/ first coords to get back into Cowan Park anyway.
Please bring a pen to sign the log. In COVID19 times a DM'd photo of the cache container would also suffice.