Los Nevados is a national park centered on some snow covered volcanic peaks; Nevado Del Ruiz, Nevado del Tolima and more. The park is run by a "concession" - Concesion Nevados - Which actually is the travel agency Aviatur. Although not ruining the park entirely, it does feel more like an alpine resort than a national park. In practice this means that the park is privatised and that the goal of the park is to shuttle as many people as possible up the roads and down again.
Flora and fauna
Very interesting flora, layered in different heights.
Fauna within the park ranges from the Spectacled Bear (Tremarctos ornatus), the Puma (Puma Concolor)and the Tiger Cat (Leopardus tigrinus).
Though rare, the Andean Condor (Vultur gryphus) can be seen soaring at high altitude above the park.
Reasonably cold. Expect frosty mornings (0 to -10 °C) year around. In the wet season, expect clouds continuously, in the "dry season" expect clouds and rain 10AM to 3PM, and clearer conditions before and after.
The usual way to get in is from Manizales. From there you have several options: Go on a tour and jump off (120,000 incl. entrance and breakfast), Taxi (COP$300,000) take a bus to the intersection and hike or hitchhike up. The last option is the best one if you have the time, as you would gradually acclimatise to the altitude, not pay excessively, and avoid the extremely commercial feel of the Concesion.
Fees and permits
Entrance fee is COP$53,000 for foreigners, COP$33,000 for Colombians and COP$6,000 for Colombian students and kids between 5 and 12.
The only outdoors store in Manizales - Amazonas Deportes near the cathedral has a pathetic selection of gear another option is hire some specialized guides, these guides offer gear rental service, this little business is called "Zion Integral Mountain Guides" and you can find them in the facebook.
They sell food at most of the old refuges which have been turned into shops.
They sell beverages at most of the refuges as well.
Hotels or camping.
There are two hotels in the park, El Cisne and Hotel Los Termales. Do not go to El Cisne thinking that you can get a room on the spot. Reservations can only be made in Manizales.
There are campsites at El Cisne and the Chalet. You are required to have a tent if sleeping at the campsites, if you sleep in a bivvy bag they make you sign a waiver that if you die it's not their fault, and that they warned you. Get a tent anyway because it rains so much that you will need it to keep things dry.
Temperatures at El Cisne campsite are said to drop down as far as -17°C at night so ensure you pack warm clothes and have a good quality tent.
You can camp anywhere you like.
Maps are not available anywhere in Manizales or the park itself. The only map you will get is the cartoon map you see on the website of the concession. Apparently the only place you can buy a map is in Bogota, from the Geographic institute (Sigac).
This is a fairly high area and altitude sickness is a serious issue. It is highly recommend to get acclimatised at 3000 and 4000 m before setting out on any climbs.