Has anyone been to these places in Colombia?

I found a few more places that look very interesting to go visit while I live in Colombia. I have read about them on websites and still have a few questions. If anyone has been to these places and can elaborate I would appreciate it:

River of 5 Colors:

How many days do I need to see this?
Instead of walking the last hour, can you ride horses?( I have some nerve damage in my neck and it is difficult for me to carry my water and a backpack)
What is a good tour company to use for this trip?

Bahia Solano:  I will be taking friends from the USA here.

Does anyone know a really nice place to stay here?

We also are going to see Cartagena. Is it worthwhile to spend a day or 2 in Barranquilla. If so, where should we stay and what should we do? I have heard conflicting opinions about Barranquilla.

Any other details about these places that would make the trip better would be appreciated.

Thank You in Advance.

i wouldn't spend time in Barranquilla but Cartagena is awesome - 2-3 days is enough.
Medellin is the best !

Cartagena is great.  My wife and I stayed at Hotel San Martín.  It is 2 blocks from the beach, economical and comfortable.  We were very pleased with the accomodations.

Hi!
Regarding Caño Cristales (river of 5 colors), here are some information.
Usually, a 3 days / 2 nights package is enough. A longer stay would mean re-doing what has been done the day before.
Usually people travel to Villavicencio, and then take a small plane to La Mararena.
It's then 20 minutes of canoe, then about 6 miles of 4WD ride to Finca David, which is the entry point for Caño Cristales.
It is roughly 1 hr walk, with some difficulties. Keep in mind that it is very hot too. Yes some tour operators offer horse riding.
Keep in mind that from Villavicencio, comfort is minimal. These small planes can be frightening. Hotels in La Macarena are very basic. and then canoe ride, 4WD ride on a so-so trail... With physical limitations, I would think it twice.

Barranquilla is not a touristic place for a reason: It is ugly.  Ok, not ugly, but well, nothing interesting to see. Barranquilleros are fine people though.

Hi, Barranquilla is nice, the north part of it or Puerto Colombia, they have very nice hotels in Puerto Colombia. Do not go south and be careful with the metropolitan area, some spots are very bad.