Rincon de La Vieja is an inactive volcano near the Nicaraguan border in Costa Rica. There are a number of trails that can take you all the way to the top to see the sulfur lake (8 hrs round trip) as well as hikes to see the secondary effects such as boiling mud and sulfur pits, and waterfalls (only 2 hours round trip). The hike is not too strenuous and is very cool. I was hiking with a group of my friends and we found it to be really fun. The initial hike really shows the diversity of Guanacaste's ecosystem, were you can see the famous tropical dry forest and the brush "desert" similar to that of Arizona.

In the "desert area be ware that there are rattle snakes. While the rattle snakes are not nearly as aggressive as those in the Southwestern United States, they are still dangerous. After you have hiked around the Volcano take a small hike to a freezing cold river. It is gorgeous there even though the water is very cool, it feels refreshing. I  would definitely recommend walking up the river to see the small waterfall or walking down the river to see a bigger waterfall and go cliff jumping. But be careful, it is high up and can be slippery, stay as close to the forest as you can.

Be prepared to see lots of pizotes, agoutis, and even the occasional monkey. TIP: Never lean or touch any tree or rock in Costa Rica. On larger trees there are spiders, boas, and even scorpions. Smaller trees like the acacia tree have poisonous ants that give an extremely painful sting. An Acacia ant sting will give you pain for about 4-5 minutes unfortunately there is no medical treatment you just need to wait five minutes and the pain will go away. Also be ware of long lines of black ants that may march across the path. Do not go near them, the ants are called army ants and will ambush you, their bites are painful! Wait for the ants to pass or go on another path. It's not worth it to mearly walk through them. These tips would normally be given by the staff at the park but they only speak Spanish so unless you are fluent you are going to need to remember these.