The dark history behind Madeira's famous levadas

 Fundamental to Madeiran identity, its 3,100km of aqueducts have proven to be more than a clever and functional feat of engineering to colonise an isolated island.

Located 560km off Africa's north-west coast, the Portuguese island of Madeira is full of dramatic hikes like the Levada do Caldeirão Verde, or PR9, that wind like veins through the island's picturesque landscape. What's unique about these trails is that they run alongside the island's slow-running levadas (man-made irrigation tunnels), providing awe-inspiring moments at every turn. These innovative water channels filter down from mountainous highlands into villages, towns and cities, providing not only handy navigation routes for hikers but water for cultivation, power and drinking. More impressively, they journey through some of Madeira's wildest forests, skirting vertiginous mountains that fall steeply into the North Atlantic Ocean.

While Madeira's levada system doesn't stand alone – Switzerland, the Canary Islands and Oman have used similar methods of transporting water – its location is distinctive. The island's volcanic topography emerges dramatically from the ocean, sprouting vast, immense mountain ranges, including its highest peak, Pico Ruivo, at around 1,860m. The woodland is so dense that when navigator Alvise Cadamosto arrived in the 15th Century, he remarked, "there was not a foot of ground that was not entirely covered with great trees".

Today, however, the levadas are taking on yet another new role: changing the face of tourism in Madeira from being known as a sedate winter getaway for Brits in their golden years to an island destination for young thrill-seekers keen to be challenged by its hair-raising paths (it's recommended to hire a guide when hiking the island's more dangerous trails).