Costa Rica Activity Pictures

...try one of Costa Rica's famously unflagging white water river rides. Then there's...

Due to the country's regular, heavy rainfall and hilly topography white-water rafting aficionados and kayakers have a superb variety of wet river runs that are the envy of most other countries and attract activity professionals in training from all over the world.
San José is close enough to a couple of serious rivers to offer day trips out to the Reventazon or Pacuare, or longer excursions further away. La Fortuna also provides trips out to several fine rivers, as does Quepos in the Central Pacific, or head for the white-water capital, Turrialba in the Central Valley.

Costa Rica's rainforest, such as this section near La Fortuna. Which you can travel via hi-speed cable or...

One of Costa Rica's more popular adrenalin activities is the flying fox [otherwise known as a wire slide or zipline] tour, where you slip on a safety harness, clip on to a wire and rocket from one tree-top platform to the next, hoping not to plummet to the forest floor 80m below.
There are close to a hundred operators in the country but choose wisely and not necessarily the cheapest - there is a safety factor involved, so ensure that equipment is in good shape, fits snugly and your guides are sensible and sober.
Skytrek [3hrs, 2km/1.25m] in Monteverde [private] Park offers the biggest wire slide, including one 400m slide, with 80m suspension bridges.

Alternatively for those who wish for more forest study and less speed, canopy tours include high suspension bridges [sometimes known as sky-walks] and platforms from where travellers can eyeball wildlife horizontally, getting a far better view of monkeys and birds than is possible from the ground.

...if you prefer to hike through the rainforest instead of scooting over it at speed, this is the kind of scenery you may expect. Hikes can be an hour, half a day, a day, several days, with guide or without, well marked trail or not, all options are open in the 'jungles' of Costa Rica.