http://www.bedfordcounty.net/GRAVITYHILL/
is this for real?? is there really a hill where your car will roll upwards? also stated that water flows up hill too, how is this possible? baffled here, gotta be some kind of an illusion, any of you fellow americans ever visited it?
I’m sure this topic has been covered before, but I don’t want to burden the hamsters with a search. In short, no it’s not possible. It’s simply an optical illusion that makes it appear that you’re going uphill when, in fact, you’re going slightly downhill.
Its essentially a hill on a hill…
Yeah, I’ve been to one of these places when I was but a lad. The one I was at had build several rooms off-plumb, so it would appear that everyone was standing crooked. A very convincing illusion among others… like water running uphill, which of course, the grade of the water-run looked like it was downhill, but it was built upon tilted ground, so the net angle was in favor of the water appearing to run backwards. A novelty-type tourist attraction, but nothing more.
Actually, I live close to Gravity Hill and went there a few times as a kid. It is an optical illusion, but a VERY convincing one. I think it’s cool for kids to go too, and adults, cuz it still looks neat. 
still don’t get it. this (http://www.post-gazette.com/columnists/20021114diana1114fnp1.asp) reporter seems quite convinced by it. could someone maybe draw up a diagram of the optical illusion, i just can’t understand how a car rolling up hill can be an optical illusion!
Because the car rolls downhill, not uphill. The optical illusion is in the visual clues as to what is level, what is uphill and what is downhill. The clues in this spot are such that what you think is a slight uphill grade is actually a slight downhill grade.
See a couple of these older threads for more information:
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=164275
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=34731
Here’s an explanation of mystery spots, which works the same way as the Gravity Hill:
Basically, we humans aren’t very good at sensing the direction of gravity. We rely heavily on visual cues to determine the vertical direction, such as the horizon, trees, and artificial structures. When all those visual cues around you are systematically skewed, an uphill road can look like a downhill road.
I’ve been to the Gravity Hill in Moncton, NB and they make sure that the water flowing down a stream is quite visible.
But in Moncton, you can also see a tidal bore. And that’s no optical illusion. The water in a river does reverse direction temporarily. It’s quite cool.
When you see one of these places, you’ve got to ask yourself: If that car is rolling uphill, then how the heck are you defining “down”? Because it seems pretty reasonable to me to define the direction the car rolls as downhill.
Actually, they call it “Magnetic Hill” in Moncton, NB. The illusion had absolutely no effect on me. Perhaps I know too much? I recall being instructed to pull my car forward to a designated spot. The spot was very slightly up a subtle incline. Then, the car coasted backwards when placed in neutral with the brake released.
It seemed nothing more to me than Galileo’s experiments starting a ball on one incline and observing it roll up another incline. However, in this case, both inclines were very shallow. Nonetheless, I didn’t feel nor observe that I was going against gravity. But, like I said…maybe I know too much?
Some claimed to have observed a similar effect in the NW suburbs of Baltimore, too…on a lesser-travelled, winding road. But, I never tried it. It’s on a public street in “the sticks” (boonies), and I think some have tried it late at night.
Not sure what all the hub-bub’s about, bub! 
- Jinx :dubious:
Just wanted to add: When BobT (above) speaks of rivers reversing their direction of flow, that is not related to any real trick of gravity nor any optical illusion. It is the tremendous tidal flow of the Bay of Fundy. When the tide comes in, baby, it COMES in! The Bay of Fundy is known for having the highest tides in the world. In fact, a good portion of the channel (between Nova Scotia and New Brunswick) empties out when the tide goes out. So, you can imagine the force of the water when the tide comes rushing back in! Thus, you can picture how rivers are forced to flow upstream when the tide comes in - due to the overabundance of water rushing in.
In short, normally rivers empty into the Bay of Fundy. However, when the tide comes rushing back in, the water flows from the Bay of Fundy causing rivers to flow upstream. At St. John, NB, the effect is even more pronounced better known as the “Reversing Falls”. It’s worth the stop when in New Brunswick. - Jinx
One of the duller traditional diversions in amusement parks are “crazy houses” where the conventional rules of gravity appear to be suspended.
I recall visiting such a place at a Six Flags amusement park when I was a boy. As one entered the house one headed down a hallway where the floor was slanted at a various angles for a series of intervals. Eventually one became disoriented so that it appeared one was standing on level ground when one was not.
One then passed open doorways which opened onto rooms where the floors appeared to be slanted. Actually, the floors were level. Either that, or they were slanted, but not in the ways one thought. In one such room, I recall, a young woman had the tedious job of continually striking a cue ball so that it rolled “up” a pool table and then appeared to cling to the slanted surface as it came to a stop.
The various “magnetic hills”, “magic hills”, “devil’s hills”, “vortices” etc. work on a similar principle. It appears that one is moving along ground that is slanted in a particular way, but is not.
There is a place in Illinois near St. Louis, Missouri, where a state highway crosses some railroad tracks. One night a friend of mine was stuck in traffic at this intersection when he let his foot ease off of the brake. The car began to roll backwards, which seemed to mean that it was rolling uphill.
Startled, he took a look outside of his car and saw that the ground did, in fact, descend behind him, though at a very slight grade. The ground to either side of his car which he could see from his windows, however, had a reverse grade–it did slant upwards behind him. Because he could only see this ground while he was inside the car, he had the impression that he was rolling uphill, while, in fact, the opposite was true.