The Overtoun Bridge in Dumbarton Scotland was built in 1895. On the bridge, over 50 dogs have died from the fall, while over 600 have survived after jumping.
These dogs usually act normal until they get close to the bridge, then they'd run off and jump. They usually jump from one side of the bridge, and there are reported cases of dogs that after surviving the jump will get back up again jump again.
The explanation given by the science community is the presence of strong scent, like that of the mink urine, combined with that of pine martens that stimulates the dogs' hunting instincts, causing them to jump.
Yet, there are superstitious stories also.
In 1993, a 33-year old man was reported to have thrown his infant son over the bridge, believing that he's incarnated from the devil. Later, the man attempted suicide by jumping off the bridge.
According to locals, dogs can see spirits, so when they get to the bridge, they see the ghost of the baby (Devil) and jump to it.