My first big adventure in Colombia was the 3 day hike to the
Lost City, known in Spanish as La Ciudad Perdida. It was another one of those great undertakings I hadn't planned at all. The tour starts from Santa Marta, that's also the place to go to the wonderful Parque Tayrona. Everything is included but please do consider giving a tip to the cook (he carries the food of up to 6 people along the way).
I can highly recommend this amazing hike. If you've been there feel free to share your experiences.
Read more about my trip to the Lost City
Best wishes,
Mark