With snow-capped peaks tumbling towards the turquoise waters of the Caribbean, the Sierra Nevada de Santa Marta National Park is one of the jewels in Colombia’s tourism crown. But behind the picture-postcard views lies a more sinister reality. Armed groups are holding local businesses to ransom and terrorising Indigenous communities. The signing of a 2016 peace deal between the Colombian state and the Revolutionary Armed Forces of Colombia (FARC) ended more than half a century of war and helped propel a country long associated with druglords and rebels onto the global tourism stage. Since then, thousands of visitors have poured into the Sierra Nevada each day, trekking through pristine jungle to white-sand beaches or climbing towards Colombia’s mountaintop Lost City, which predates Peru’s Machu Picchu. Few notice the men in camouflage watching from a distance.…