Signs at every trailhead tell visitors to stay on the walks. A walk in the park "looked like no risk at all," Piedrahita said, but he was worried about losing his cell phone, so he had left the phone in the safe at the hotel where he was staying. When he took the dirt trail, he figured the fact that it wasn't built up meant there was no need for boardwalks, he said. I never thought of the swamps," he said.

"I could never find my way across what appeared to be the wider part of the swamp," he said.

"To survive, he said, he ate a few plant stems. "For drink I had to use urine," he told reporters.

...kidney problems resulting from dehydration and little food...