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The Fortress of Kuelap is one of Perus hidden archaeological treaures, often called the Machu Picchu of the North Built on a mountain ridge at an altitude of 3000 meters above sea level, the fortress is proof of the incredible stoneworking skill of the Chachapoyas people, who dominated the region between 1000 and 1400 AD. The gigantic wall that protects the city includes a series of guard posts, a tower built overlooking a sheer cliff and three narrow entrances that forced invaders to enter in single file. The wall reaches a height of 8 meters and extends for more than 600 meters to completely encircle the ruins. The city inside is made entirely of stone, but in a very different architectural style from the Incas, with carvings of human faces and animal figures lining the main entrance passageway. A string of geometric shapes, rhomboid stonework is built into the walls of most buildings.