The Overtoun Bridge is located near Milton, Dumbarton, Scotland. It was built in 1859 and has become famous for the number of unexplained instances in which dogs have committed suicide by leaping off of it.
The tragic incidents were first recorded between the 1950's and 1960's when it was noticed that dogs - would suddenly and unexpectedly leap off the bridge and fall fifty feet to their deaths. In some cases, however, the dogs would survive, recuperate, and then leap off the bridge again. The locals have a name for these dogs: second-timers.