Are gravity hills real? How to check out 5 in Alabama

Article Excerpt: "... Go to the stop sign where Gravity Hill Road intersects with Alabama Highway 280 in Oak Grove, near Sylacauga. This is Alabama's most well-known gravity hill, mainly because the name of the road was changed to reflect the odd occurrence. The spot will come up when typed into a GPS, or try using the address 117 Gravity Hill Road, Sylacauga..."

Reference: www.al.com