Should be enough for one day's posting. I don't want to swamp everyone. This is a picture taken while still in the Tortuguero park area. You can get a decent idea what the jungle looks like, at least vertically. Quite dense in most areas. Three species of monkeys (howler, capuchin, and spider), many species of snakes and other reptiles, bugs, spiders, and God knows what all else.
Not far from where this pic was taken (we pulled up near shore in the boat) was where we stayed for two nights. Small cabanas, no AC, no windows...just low 3' walls, screen material, a bedroom that led to the simple bathroom. Not fancy, and high humidity and quite warm. You had to be careful walking on the floors, not only because the humidity made the tile floor slick (I swear, every place in CR has tile floors), but to watch out for large spiders which, as I found out, also jumped.
We'd go to sleep at night, listening to the sounds of the nocturnal creatures, and wake around 6 to the sound of the diurnal critters, including the very loudy and abrasive howler monkeys (and many different birds). It's a little freaky staying in jungle this dense, with only a little screen between you and all outdoors, and hearing a monkey barking not too far away.