It is considered one of the creepiest places on earth. The Overtoun Bridge of Scotland is also known as the "Dog Suicide" bridge. It is said that an average of one dog per month leaps to death from that bridge since the 1950s. This unexplained mystery raised the question of "why?" so Scotland tried to solve the mystery by sending an animal habitat expert to investigate. Dr David Sands concluded that the dogs were not following a voice or something they saw but they were probably drawn by a scent. After some research and tests with dogs, the explanation that was given is that the dogs were possibly drawn by the scent of a mink. Although Sands never said that it was a definitive answer.
Some photos of the bridge and the documentary at the end: