A salt road (also known as a salt route, salt way, saltway, or salt trading route) is any of the prehistoric and historical trade routes by which essential salt has been transported to regions that lacked it (see History of salt). From the Bronze Age (in the 2nd millennium BC) fixed transhumance routes appeared, like the Ligurian drailles that linked the maritime Liguria with the alpages, long before any purposely-constructed roadways formed the overland routes by which salt-rich provinces supplied salt-starved ones.