Tayrona National Park has, without doubt, some of the finest beaches in all of South America - this is a tropical paradise. It's hard to put into words quite how beautiful the empty beaches of Park Tayrona are - you'll have to visit. This is one of Colombia's real travel highlights - there are miles of unspoilt beautiful rainforest backed beaches - the only complaint might be that most are not safe for swimming. There is also only one real hotel in Park Tayrona (the luxury Eco-Habs), though there are various places for camping, and many sites offer hammocks for rent. Most of the campsites have small rustic cabanas that you might be able to stay in, if there is room upon your arrival.
Note that technically you need a Yellow Fever certificate to enter Park Tayrona. In reality, this is very rarely requested at the Park entrance gate. If a Yellow Fever certificate is requested and you don't have one, try coming back the next day, or just take a boat from Taganga or Santa Marta and avoid the entrance check (though the boat will be expensive).
Canaveral & Eastern Park Tayrona
Canaveral, in Eastern Park Tayrona (see map), is the most frequently used, and convenient, access point - it's less than 1 hours travel by car / bus from Santa Marta or Taganga (a taxi costs 60,000 pesos). Supposedly you are meant to have a yellow fever vaccination certificate to enter the Park, though this is rarely checked. At Canaveral is the luxury Eco-Habs hotel (no website - book through Aviatur). This luxury spa hotel offers guests beautiful individual cabanas - make sure you request a room with an unobstructed sea view. Eco-Habs is rather expensive at 440,000 pesos per night for two people - though interestingly is is exactly the same price for a group of four people. There are some lovely beaches near Eco-Habs, and this section of Park Tayrona feels far more civilised than the beaches further West - there's excellent food and cocktails served by Eco-Habs on La Piscinita beach for example (relatively safe for swimming).
Arrecifes & Cabo San Juan (Eastern Park Tayrona)
Having arrived by taxi, or collectivo, at Canaveral, most visitors travel onwards to the campsites a short walk West of Canaveral. 45 minutes walk West is Arrecifes, the best base to explore Park Tayrona. Donkeys can help transport your bags to your campsite & restaurant there (and also to the campsites further along the coast), though the fee is not particularly cheap. Aviatour operate a campsite at Arrecifes, which also offers hammock spaces for 16,000 pesos - this is the best campsite in Park Tayrona. Walk a little further West (in the direction of Cabo San Juan) to find La Piscina beach, which is Tayrona's only truely safe beach for swimming.
A further 45 minutes walk west of Arrecifes is Cabo San Juan - another campsite and restaurant is present. The campsite here is poorly managed, and the restaurant food rather dubious, though this is one of the cheapest accommodation options in the Park. The campsite at Cabo San Juan has one of the most beautiful settings of all accommodation options in Park Tayrona. Further West still one finds Park Tayrona's finest (empty) beaches - just follow the paths westwards to find 3 fantastic beaches. The last beach one can walk to is a nudist beach. Alternatively, as one leaves the campsite in the direction back to Canaveral (ie. East), follow the path immediately on the left as you exit the campsite, to find a tiny bay and beach a short walk away. Keep walking round the coast another five minutes and you'll find yourself at La Piscina beach - the largest, and most empty part of this beach, which is only accessible by this route.
There's more than just beaches in Park Tayrona - walk a little inland to Pueblito, a small but fascinating indigenous village (the indigenous people in this region of Colombia are called the Tayrona Indians).
Western Park Tayrona
The Eastern section of Colombia's Tayrona National Park (Canaveral, Arrecifes and Cabo San Juan) is the most visited, most beautiful, and also most geared towards tourism, but the Western section provides an interesting alternative.
It's easy to arrange a boat tour from either Taganga or Santa Marta to visit the Western region of Park Tayrona, at a cost of approximately 300,000 pesos. The sea is usually extremely rough. There are a few campsites and restaurants in this region.
Furthest East from Taganga (but West of the region accessible from Arrecifes) is Playa Cristal (the bay near Bahia Cinto marked on the map), found in a large cove that is scattered with numerous other small beaches. The water is very calm here, unlike the rest of Park Tayrona, and there is also a spectacular salt plain. There is also a campsite - but there is no restaurant, or running water. Nonetheless this is a beautiful alternative to the more commonly visited camping zones further East, and there are various small beaches that can be walked to. Playa Cristal is accessed by boat only, though once you do arrive, those wishing to leave by land might be able to do so by following the trail to the main road to Santa Marta - it's a four hour walk to the road, where it's easy to pick up a bus.
Further West in Park Tayrona lies Playa Neguanje. This long beach can be accessed by road - collectivos depart daily from Santa Marta, or you can arrange a taxi. At Playa Neguanje there is a restaurant, as well as a camping zone, but again no running water. Neguanje is a large beach, but can get busy on weekends as it fills up with day trippers from Santa Marta.
Slightly further West from Neguaje is Villa Concha (marked Bahia Conca on the map), where again there is a camping zone, but with no facilities. Villa Concha can also be accessed by road.
Here's a travel tip - check out Google Maps for detailed images of Park Tayrona - print them off before you visit, and use them to find some truely empty and idyllic beaches in Colombia.