We went for 3 weeks before we had children. It was amazing! I'd love to go back with the children!
Highlights included:
kayaking at dawn through alligator infested waters on the carribean coast with howler monkeys in the trees over head.
Flocks of pink flamingoes glowing in the setting sun.
Bathing in hot springs at the foot of an active volcano (Arenal coughs lava pretty much constantly which is incredible to watch after dark).
Canopy walks through the forests seeing butterflies the size of two adult hands and exquisite tropical birds.
Watching turtles lay eggs in the middle of the night.
White water rafting.
Holding a toucan on my arm.
The diversity of flaura and fauna is sensational. I think your boys will love it!
Downsides - food isn't very varied. I ate rice and beans every single day (vegetarian). But there is masses of fresh fruit.
There are mozzies (honestly don't remember spiders as pp mentioned - and I am pathetic about spiders. Poisonous frogs and leaf cutter ants, beautiful bats, fireflies... but nothing that bothered me). Use a mozzie net religiously. Every room we stayed in had one. I sprayed the net with deet before bed, preferring not to put it on my skin. I also added a couple of drops of lavender & citronella essential oils to a handful of body lotion and covered myself in that (natural repellent). May have had the odd mosquito bite but travelled down the mosquito coast with very little problem.
I carried a loo roll around in my back pack. Not necessary most of the time but as we were travelling around a lot sometimes useful. Ditto wet wipes for a freshen up.
Architecture is nothing to write home about. As they regularly have earthquakes they don't build lavish constructions. I think the opera house in the capital was the most (only) ornate building I remember.
A pp mentioned journey times - the journeys were part of the adventure! Bus journeys through banana plantations, boat trips through lagoons. All the journeys offered so much to see!
Enjoy! X