You leave beautiful Tilcara by a dirt road and cross a large iron bridge where you discover a huge landscape covered in yellow poplar. You walk a little more, and climb a small hill. At the top you'll discover the Pucara, or fortress, that was built by the 'tilcaras' (native to the region) more than 900 years ago. It's a magical place with fabulous views over the valley of the Rio Grande and Quebrada de Humahuaca. Half rebuilt, the Pucara is amazing and especially suggestive. If you're fortunate to visit with only a few people, you'll be flooded with a strange energy.