Hurry !
where was the "lost city" of machu picchu located, and why was it "lost"?

It is located in the Cusco Region, Urubamba Province, Machupicchu District, above the Sacred Valley, which is 80 kilometres (50 mi) northwest of Cuzco and through which the Urubamba River flows, cutting through the Cordillera and creating a canyon with a tropical mountain climate. When the explorer Hiram Bingham III encountered Machu Picchu in 1911, he was looking for a different city, known as Vilcabamba. This was a hidden capital to which the Inca had escaped after the Spanish conquistadors arrived in 1532. Over time it became famous as the legendary Lost City of the Inca.

Interpreting the results of his experiment : )