In the picture you can see a huge spider I saw in the bushes in Puerto Viejo. The main danger in Puerto Viejo are not spiders, but sand flies. The only way of repelling them, is by using a good bug spray.
North of Puerto Viejo there is the town of Limon, where Columbus landed on his last voyage to America in 1502. Limon is Costa Rica's biggest port. The town has not much tourist interest.