Ciudad Perdida
There are also things to do if you are more interested in adventure and one in particular is The Lost City, also known as Ciudad Perdida. In order to reach the city you must devote 5-6 days getting there, but it is worth the wait.
Mompox
Another hard to get but worth the effort places is Mompox. It is located on an island which sits on the Magdalena River. Due to the help of many organizations the architectural details native to the island have been very well preserved.