Due to the nature of these cache containers, please be careful to place them right back where you found them so muggles won't notice it.
You are seeking unusual containers hidden in plain sight.
You can walk right up to the cache location. You will need to be able to step over an obstacle but DO NOT CLIMB ON THE trellis or ravine bluff. It is not necessary to retrieve the cache.
Fort Sheridan used to provide steam heat and electricity to all its buildings from centralized plants. Piping that ran underground ran the heated liquid and power lines to all the buildings and in some points these connections had to cross ravines in overhead trellises.
Today the buildings are heated by the home furnaces of the remodeled residences. General Sheridan would be pleased with how the propert has been preserved.