FOXBORO -- If you're one of the thousands of fans who will make their way here for training camp at some point this summer, there's a good chance you'll see the Patriots finish up a session by disappearing briefly over a ridge in the back corner of the Gillette Stadium practice fields.
By the time players reappear for interviews or autographs, they'll be drenched with sweat and out of breath.
"Mount Belichick," Bill Belichick said after one particularly grueling workout last year. "That's what they called it back in Cleveland."
Patriots players haven't taken the time to name the New England version, probably because none of them really like to think about it all that much in their free time. But unofficially, the space is known as The Hills. Oftentimes there's an expletive mixed in, as in "Those [Bleeping] Hills."
This out-of-sight slice of the team's work space can be a year-round tool, but it has seen regular usage every summer since it was installed about four years ago. For an organization that harps on the importance of being able to outlast opponents, running The Hills is believed to be a difference-maker.
"That hill's great," director of player personnel Nick Caserio told Sirius XM Radio recently. "That hill gets them in shape pretty quickly. Those guys don't like it, but they'll probably in the fourth quarter realize it's worthwhile."
"It definitely teaches you how to become comfortable with being uncomfortable," receiver Danny Amendola said. "It's a beast, for sure."
There are actually two hills on the south end of the practice fields that slope down to a flat turf landing. They have different gradations. One is 20 yards long and steep. The other is 60 yards long and features more of a gradual incline.
Neither provides any escape from the heat, but these are not the dry and rocky hills with treacherous footing that you might find on in an old-school training camp video montage. No, these hills are as well-manicured as the rest of the Patriots practice fields, with white lines painted every five yards so that players know just how much farther they have to push when their legs are pleading with them to stop.
The mere mention of The Hills to players during last summer's training camp was usually met with shaking heads and nervous laughter.
"It's a little bit of a drain, but it's kind of like taking medicine," said left tackle Nate Solder. "You know you need it."
"The Hills are a beast, man," said former Patriots receiver Brian Tyms. "It's like that one bully you have in school. You're like, 'I hope he doesn't mess with me today.' That's what that's like. It's just the incline of it. It's real. It makes a man out of you.
"Jerry Rice. They said he ran a 4.7 [40-yard dash] but he could run a 4.7 every play. A lot of people who run a 4.3, but in the fourth quarter they can't run a 4.3. Conditioning is like the biggest thing in football. Everybody's an athlete, but how many times can you get out and exert that same amount of effort? Every play? Same intensity? That hill helps that."
"It's tough. It's a challenge," said corner Logan Ryan. "I think the hill just makes you a little bit tougher. Your legs get a little heavy and then you gotta run these sprints up a hill. Your legs, you gotta keep your mind sharp. You gotta just attack it. That's how we go about it. We feel like we get an edge in conditioning over some other guys because of how hard we go at it."
The Hills aren't only reserved for these types of conditioning runs, where as many as a dozen or so players will sprint up together at the sound of a whistle that will likely be worn by first-year head strength and conditioning coach Moses Cabrera. They can be used by players rehabbing injuries or trying to improve their speed.
They provide a space for team-building purposes, too. When the Ice Bucket Challenge to benefit ALS research went viral in 2014, the team filmed its team-wide water dump at the top of The Hills.
It's also one of the few places where players and coaches can compete side by side. Belichick hasn't run The Hills in some time, but his son, safeties coach Steve Belichick, has been seen hauling uphill. Same goes for receivers coach Chad O'Shea, corners coach Josh Boyer, defensive line coach Brendan Daly and others.
Things get competitive on The Hills. Regardless of how difficult the players just had it during that day's practice, they're sure not to get beaten by one of their more fresh-legged coaches.
"I don't care how much I ran," Ryan said. "I've never seen a coach get past me."
At their core, though, The Hills are about conditioning. Tom Brady has been seen doing resistance-band training with team staffers on The Hills, and sometimes players will make their way over there on their own simply because they know they need the extra work. Newly-acquired Patriots defensive tackle Terrance Knighton -- who is listed at 6-foot-3, 355 pounds and has target weights written into his one-year contract -- hung back on The Hills for a few minutes of cardio with Cabrera after an OTA practice last month.
Matthew Slater is touted by many on the Patriots as the team's fastest player when it comes to its punishing post-practice sprints. He credits his work on the hill behind his childhood home in Orange, California -- where his Hall of Fame father Jackie pushed him to find an extra gear -- for preparing him in that regard.
He'll take on The Hills again soon, perhaps as early as Thursday when camp opens. Whenever it happens, Slater knows there will be players who will be tired. He knows there will be players who won't be thrilled to be there. But he knows what that time and sweat invested, six weeks before the start of the regular season, might mean for the Patriots months from now.
"I think you put down the foundation in the offseason," Slater said late last season, "in training camp, early in the season, in regards to your conditioning. That's going to have to carry you all the way through February, hopefully. That's paid dividends for us, and hopefully it'll continue to pay dividends for us."