Levadas
The island of Madeira is wet in the northwest but dry in the southeast. In the 16th century the Portuguese started building levadas or aqueducts to carry water to the agricultural regions on the south. The most recent were built in the 1940s. Madeira is very mountainous, and building the levadas was difficult and often sentenced criminals or slaves were used. Many are cut into the sides of mountains, and it was also necessary to dig 25 miles (40 km) of tunnels, some of which are still accessible.
Today the levadas not only supply water to the southern parts of the island but provide hydro-electric power. There are over 1,350 miles (2,170 km) of levadas and they provide a remarkable network of walking paths. Some provide easy and relaxing walks through beautiful countryside, but others are narrow, crumbling ledges where a slip could result in serious injury or death.
Two of the most popular levadas to hike are the Levada do Caldeirão Verde and the Levada do Caldeirão do Inferno which should not be attempted by hikers prone to vertigo or without torches and helmets. The Levada do Caniçal is a much easier walk, running 7.1 miles (11.4 km) from Maroços to the Caniçal Tunnel. It is known as the mimosa levada because mimosa trees are found all along the route.
-------But a 'Levada' such as described here, built by the Portugese, is harddly an AQUEDUCT...IS IT?