The Green Swamp is a half-million acres of preserved space in the fastest-growing part of the state and the birthplace of four major rivers.
But even though it's sandwiched between two of Florida's largest cities, few people may have heard of it.
We took a three-day trek to bring you a closer look.
On day one, we walked about 4 miles from the put-in site off of Rock Ridge Road in northern Polk County. We took a trail that parallels the Withlacoochee River. It flows 100 miles downstream into the Gulf by Crystal River.
The area is just palmettos and pines — like what pioneers must have first seen when they came here hundreds of years ago.
We didn't see another soul there. The only sound was the wind whispering through the trees.
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When you look at a satellite map, it's giant green space hemmed in on two sides by the spreading grayness of Tampa and Orlando.
But the Green Swamp may be a misnomer.
Sure, it's wet in the summer and the source of the Hillsborough, Withlacoochee, Peace and Ocklawaha rivers.
But this is the driest part of the year, and water in most places is nowhere to be found.
After settling into a campsite on the Florida Trail called Concession Stand, we broke out an emergency water filter to boil the very brown water we collected from the bottom of a dry lake. We then had to filter it again through a T-shirt. That shirt will never be worn again.
The water tasted a little gritty as we hunkered down for the night.
On the second day, the sun could be seen peeking through the trees around 8 a.m.
The Green Swamp is called the hydrological high point of Florida. It's basically a water tower for a good chunk of the state. That's why so many rivers start here.
It's an important enough place that this area was preserved years ago, a good chunk of it after Hurricane Donna swept through in 1960, and flooded much of Tampa. And they preserved areas along the Hillsborough River and upstream along the Withlacoochee.
Because of that foresight and the Tampa Bypass Canal — built to divert Hillsborough River floodwaters around the city — downtown Tampa has not been flooded since.
In the 1970s, this was designated an Area of Critical State Concern, which gives it more protection from development.
"I can only imagine if it wasn't protected back in those days and if it had become, you know, condos and Walmarts and subdivisions. Thankfully, there was some foresight back in those early years to do that," said Dr. Mark Fulkerson, chief professional engineer with the Southwest Florida Water Management District, which oversees much of this area.
Fulkerson does a presentation called "History and Hydrology of the Green Swamp."
He said it could have turned out very different. In the 1850s, he said an ambitious plan was hatched to dig a canal from the St. John's River to Tampa Bay, along where Interstate 4 is now. Another canal would've connected it to a chain of lakes to the north, in Lake County.
That never happened. But loggers soon came, cutting down centuries-old cypress trees at an abandoned logging camp called Cumpressco. Given enough time, the swamp recovered.
"I'm just so thankful that nothing was ever destroyed through the Green Swamp area, and it's we're able to preserve it and allow it to function naturally," Fulkerson said.
More than 30 endangered or threatened species live here. It's become one of the most important points in the Florida wildlife corridor.
There have been some interesting sightings, as well. One is Florida's version of the Yeti — the Swamp Ape. It probably didn't have good hygiene, so Fulkerson has another name for it.
"Skunk ape is the Bigfoot term for Florida. We have had groups from like Discovery Channel go in and look for the skunk ape. We've never seen one yet," he said. "We sometimes when we've given tours, talked about, oh, get somebody dressed up and have them run through the woods."
But another kind of sighting turned out to be very real — the "Wild Man of the Green Swamp."
In 1975, a Taiwanese merchant sailor escaped Tampa General Hospital. He somehow made his way to the swamp, where he lived off the land.
Hu Tu-Mei was arrested eight months later after the Sumter County sheriff saw a wisp of smoke from his campfire. Fulkerson says the Wild Man had an interesting diet.
"There's interactions of people seeing him and maybe taking a chicken or something like that, It was asked of the Wild Man, how did you survive out there, and he said, well, I ate the little piggies, and they said, little piggies, you know, like the wild hogs, and he said, no, no, no," he said. "So it turned out to be he lived off armadillos, he called them the little piggies."
Fulkerson said those "piggies" are descendants of the animals brought in for food by Spanish explorers.
Hernando de Soto explored the area in search of riches. His army discovered that the Green Swamp was so large that they had to move west to get around it. The army passed through an area referred to as the Great Swamp, located at today’s Hillsborough River State Park. From there, de Soto camped in Dade City, then traveled down the Withlacoochee River and through today’s Withlacoochee State Forest.
The heavens opened up on our last day. The cracked, thirsty ground sopped it up.
So we didn't see too many animals — just a lot of birds, owls, and sandhill cranes. Didn't see any coyotes, bears, or even the Swamp Ape.
But what we did see was a beautiful slice of old Florida. In the rain, of course.