Manuel Antonio is a beautiful beachside resort area on the West Coast of the country. The state park there is wonderful with numerous animals and beaches! The park can get crowded on weekends and is closed on Mondays. Go on a canopy or white water rafting tour as they are well worth the money.
San Jose is a large city that many would not decribe as "pretty". However, the nightlife there is definitely worth checking out along with a quick tour of local sites. Only stay there one night during your trip as there are many more beautiful places to explore all over the country!
If you enjoy learning about a country's culture/history, see the National Museum with its preColumbian artifacts & bilingual labels, and the Gold Museum, which has a jaw-dropping floor full of gold adornments that make you realize why the Spanish were so keen to conquer this area.
Arenal Volcano & Hot Springs: Don't miss out on going to the Arenal volcano include a visit to the Tabacon hot springs...what a lush and beautiful spot - yes, it is a bit touristy but there are so many different pools at the hot springs that you can always find a little peace of your own paradise. Be careful in the springs though there are volcanic rocks all within the pools that you cannot see due to the silt within the water. If staying in the area over night book a room with a view of the Arenal...if not shrouded in cloud the red lava can be seen erupting each evening - it is amazing.
Volcan Poas: This is hit or miss in regards to viewing due to the cloud cover but if you do get to see the crater with its bluish/green coloured lagoon it is amazing....the sulphur smell and the altitude can get to you so it is recommended to stay only 20 minutes. It is a lot cooler here than anywhere else - definitely wear long pants and take a jacket.
Cafe Britt: Coffee Plantation tour - yes it is very touristy but go anyway - they provide a nice commentary on how coffee is made, you see a little show and you get to sample the coffee liquor etc. You don't want to miss it.
Sarapiqui River Boat Ride: smooth ride, with great animal viewing - howler monkeys, spider monkeys, small alligators, many birds, lizards, butterflies - take a zoom lense camera
Zip Line Canopy tours: if you are thinking you will see animals of any kind this is not for you - the zip lines whiz through the trees and with the number of people making so much noise going through the rainforest you are lucky to see a bird let alone anything else - if you want a thrilling ride you'll enjoy it
Monteverde Cloud Forest: The main reason to visit Monteverde is to vsit the Cloud Forest. The zip lines can also provide thrills, but there are walking/riding tours, and suspension bridge walkways, that give a wonderful opportunity to investigate the amazing plant life--plus you can see vultures & howler monkeys, as well as incredible views, on the tour bus going down the mountain. The resplendant Quetzal is also a resident here and a trained guide can spot this shy bird ,most of the year round, that normally travels with its mate. However the best chance of seeing one is at nearby Cerro Muerte.
Cano Negro Rio Frio: A boat ride on the river is a great way to see all kinds of wild life including: howler monkeys, caimans, lizards, sloths, bats and birds of all types
