A historical curiosity!
#Lisbon – the oldest city traffic signal!
»»» Rua do Salvador, n.26, in Alfama »»»
It was useful to guide the coaches, carriages and litters who passed through this narrow street.
The rule was: who comes from above loses priority for the coach from below, since it was hard to push back the animals. This way King D.Pedro II avoided many fights and duels, with wounded and dead.