I've always wanted to experience a real jungle rain forest and the Lost Iguana is the perfect place to do so. We stayed in room 23 which was very spacious, nicely decorated, beautiful view with its own pond just outside the balcony, BUT the best part of the room for me was the outdoor shower. You walk through the bathroom and and the other side you walk into a huge two person shower room surrounded by plants but at the same time screened in so the bugs don't get in. The spring fed water is so soft too.
There's lots to do in the area as you can see from my trailer: http://youtu.be/y3L_kSKqqWw
Access road to The Lost Iguana is at the West end of the dam situated at the East end of Lake Arenal.