Such watercourses are not unique to Madeira: what is unique is their accessibility and extent. You need only venture a little way off the main roads to begin to appreciate Madeira's myriad aqueducts - for their beauty, ingenuity of design and for the courage and determination needed to bring the concept to its present glory. The island's irrigation system now comprises an impressive 2150 km (1350 miles) of channels, including 40 km (25 miles) of tunnels - and the work started centuries ago.

The earliest settlers on Madeira began cultivating the lower slopes in the south of the island, cutting out terraces (‘poios’ in Portuguese). Working with contractors (who sometimes used slave or convict labour), they built the first small ‘levadas’, which carried water from springs higher up the mountainsides to irrigate their lands. These narrow watercourses plummet downhill, rushing and frothing with energy; their banks are often festooned with wild flowers.

By the early 1900s there were about 200 of these ‘levadas’ meandering over about 1000 km (620 miles). Many were privately owned and the undisciplined appropriation of water meant that the island's most valuable asset was often unfairly distributed. In fact, by the mid-1930s only two-thirds of the island's arable land was under cultivation - and just half of that was irrigated. Only the State had the money to implement a major building programme and the authority to enforce a more equitable system of distribution.

There was plenty of water for irrigation and torrents to spare for power. Clouds driven to the island by the prevailing northerly winds are caught by the central mountain chain and rain falls abundantly in the north throughout the year, while the south coast may be relatively dry for up to six months.