What could be more intriguing than an ancient abandoned city older even than famed Machu Picchu? The Ciudad Perdida (literally "Lost City") was abandoned during Spanish Conquest and was only "discovered" again in the 1970s, though local indigenous people knew about it long before then. Deep in the Sierra Nevada de Santa Marta mountains, it remains accessible only on foot in what is easily one of Colombia's most exciting and breathtaking hikes. Known locally by its indigenous name of Teyuna, the city was built by the Tayrona people on the northern slopes of the Sierra Nevada de Santa Marta. Today it's one of the largest known pre-Columbian towns in the Americas, and the focus of Colombia's most popular multiday hike. Doing the hike is a fantastic experience, and you don't need to be particularly strong or experienced to do it, either. The landscapes and the sense of remoteness will stay with you long after you return.