The blaze, which engulfed an area about half the size of Vatican City, was started on Tuesday by farmers burning grass and debris to prepare for sowing crops. As of Wednesday, about 20 hectares (49 acres) had been hit by the blaze, the mayor of the nearby town of Cusco said. Machu Picchu, a complex of stone structures perched on top of a mountain, was built more than 500 years ago by the Incas, whose empire controlled large areas of South America from present-day southern Ecuador to central Chile. The distance of the fire has hindered the efforts of the firefighters. “We have been fighting the forest fire for two days now and it has not been possible to bring it under control, as the area is quite inaccessible,” said Roberto Abarca, director of the Cusco Risk Management and Security Office. The impressive ruins, which have made the surrounding Cusco region Peru’s top tourist destination, are considered one of the new seven wonders of the world.