Tayrona Park is one of the must do’s in Northern Colombia if you ask me. From Taganga you can take daily boat transfers to Tayrona park. Its about an 35km boat ride (1:15h), but be prepared for choppy waters. Not for everyones stomach ;o).
I actually preferred the bus option on the way into the park that takes you first to Santa Marta (calle 11/cra. 11, 20-30mins, pretty frequent, 2.5k COP) and then Tayrona park entrance (another 30-40mins, 7k COP). This works out at about half the cost of tourbus operators. The bus driver is meant to let you know where to get off, but best keep an eye out yourself. Once at the park entrance, its a 2h walk first on muddy jungle roads at least this time of the year (Nov/early Dec). My recommendation … just take the shoes off. Doesn’t hurt, looks way less embarrassing than hopping around to keep your new trainers clean and is actually healthy.
Once you managed to get through the jungle, you will get to enjoy a nice walk on the beach until you get to the swim spot (la piscina) near Cabo St Juan. On the way you’ll find camping grounds, indigenous selling coco nuts and beach restaurants with refreshments and excellent fish (I am saying this as not a big fish eater … lovely stuff).
As I mentioned above, the boat is the best way home from here. Loads are waiting with 4.30pm usually the last departures. Don’t miss it as camp sites are often fully booked in peak season. Better though, in hindsight, get your hands on one of the hammocks in the lodge at Cabo San Juan beach (though pricey, see here for details).