Go there preferably in the morning because these large natural pools and waterfalls are very popular with the locals. There is talk of a future access price of 10,000 cop.
A good 1h30 walk or more, depending on your pace, will lead you to the small waterfalls and the large natural pools. The locals are fond of the place and it can be crowded: go there preferably in the early morning or late afternoon. Be aware that when it rains, the downstream parts can be very dangerous because there are siphons or small tunnels :-(.
At the MN reception, turn right and follow the signs to Candelaria 20 min. Enjoy the coffee, dark red when ready to be harvested: from November to January, the banana trees, the avocado trees (harvested between May and July). Before the entrance to La Candelaria, turn left. The path is marked in red and yellow for the river.
You may have to pay 2,000 cop p/p when passing a private property. If you think you are lost, don't hesitate to talk to the locals. You have to cross the river on an old worm-eaten bridge or walk around it, then 20' more walking. Turn left to get to Pozo Azul and enjoy a nice cold bath.
From Pozo Azul, take the same road back to Mundo Nuevo or walk to Minca and you can even take a mototaxi. On the way to Minca you will find small restaurants and more in the city. From there you can ride a motorcycle or try to walk back to enjoy the sunset in Punta de MN. There is talk of a future entrance fee of 10,000 cop.