Tree forts another treasured memory I built several.
One I recall, in an old tall Banyon tree about 50 or so feet from Biscayne Bay (Miami) just north of the Rickenbacker Causeway I swear it was 30' up, It had 3 levels of decks.
We could see way out across the bay and in to Seaquarium no other trees anywhere near that height.
Developers cut and bulldozed it in 1960 to build the Brickel building. There was also a Limestone rock cave nearby we played pirates in, they also razed.
In October of 2016 a portion of the building under re-model collapsed.
We also use Tree fort sometimes interchangeably with tree house, some were just tree platforms and others were more elaborate with walls and tiers (2 or 3 platforms stacked)
In the case of the cave, it was a natural formation in the north area of the Silver Bluffs.
The cave was a hollow about 15' deep, 8' wide and 8' high, with huge slab of rock leaning against and covering about 1/2 the entrance. (top photo on the left)
I found these old photos on the Silver Bluff website; I am tickled to see it again
the second photo does not show our cave but does show more of the bluff.