NYT:
Told that the area was restricted, Mr. McGuire said he was unaware of that and described the island as looking “like a tropical paradise,” the report said.Here's a video from 2017 showing the condition of the island and some brief nightmarish images:
...
Discovery Island, which was originally called Treasure Island, was an 11-acre zoological park that featured aromatic foliage, trees and flowers and walk-through aviaries with more than 500 species of birds.
Online maps show that the park, which opened in 1974, had a flamingo lagoon, a turtle beach and alligator swamp. It closed 25 years later and photos and a 2017 video show the remnants of the abandoned attraction: deteriorating buildings, overgrown trees, a former animal hospital and an abandoned dock.