A great time with Desafio white water rafting. A great work out and pretty intense. Sometimes people do get hurt, but luckily our group went unscathed. A well run operation. Remember to bargain amongst the different companies when you get there!
Do not miss out on spending a day river rafting on the el toro river (Bull river). The river has many class 3 and 4 rapids and is therefore a lot of fun and will give your heart some pumping action. The scenery is stunning. There are some calm streches where you acctually will be able to enjoy it :-) There is quite some wildlife to spot as well. We even saw a coral snake or one of his nonvenomous look alikes. You can never remember the rhyme if you should to: "Red and yellow, kill a fellow; red and black, venom lack".
You can do short tours with about 1 1/2 hours on the river or one where you will be three hours on the river. Of couse the trips will vary according to the water conditions. I recommend the longer one which includes some stops and lunch.
Equipment: If you have bring some shoes you can get into the water. The tour organizer will have some boxes to keep your stuff try.
You can rent bikes or take a guided mountain bike tour from Bike Arenal, www. bikearenal.com. They have a whole fleet of well maintained mountain bikes with shocks, including helmets and small repair kits and locks. We rented bikes for a half day and rode them from the shop out to the Rio Fortuna waterfall. This is a short ride (maybe 8 kilometers?) but, wow, is it STEEP! 4 kilometers is on a dirt road that is really a workout going up hill (but lots of fun coming down!). You can lock bikes up at the top and then hike down to the base of the falls ($6 entrance fee). That is quite spectacular, and it is yet another good workout on the thighs. :-) After that, you may want to ride some more around the area and explore while you have the bike too.
Equipment: Bike rental at Bike Arenal is $12 for a half day and $18 for a full day. I am not sure what time they open, but I know they close at 5:45 p.m. and you must return the bike by that time. (It will be dark by then anyway.) I don't know how much the tours are, but I bet they are fun too.
Please note that you will need your passport in order to rent a bicycle, and at least one person in your group must leave a passport at the shop and promise to pay up to $400 per bike if the bike is stolen or damaged while in your care.