It was time for us to leave the high mountains, at least for a little while. A rapid descent from the Central Andean Ridge landed us in the fertile Magdalena Valley. Over the next week we cycled through Colombia’s heartland, bordered by the distant, blue-gray ridges of the Andes that rise nearly three miles into the sky. We crossed a wide, rushing river to reach Colombia’s largest inland desert, where we lost ourselves among strange, ghostly shapes. Then a final, quiet bike ride through the countryside brought us back to the shores of the fabled Magdalena River, among monuments to some the region’s strange, mythical inhabitants.