Costa Rica travel thread

[wiggs73]

Hi guys,

I'm going to Costa Rica this June and will be staying for about a week. I'm actually not sure where I'm staying yet, but according to Wikipedia the entire country is about the size of West Virginia, so I'm assuming anything worth seeing is fairly accessible no matter where we end up.

Fwiw, I'm 23 years old and will be travelling with 3 other people around the same age.

So what I'd like to get going in this thread is a list of things to try to see or do while we're there. And if anyone has any tips on where to say, that would be welcome as well.

So far I've found a few things that look cool.
Arenal Volcano
Hot springs at Tabacon Resort
And I've heard a lot about rain forests, particularly canopy walks and zip lines.

So give me some more ideas folks.