Because vacation time is so often limited, where you must see is dictated by where you fly in and what town you visit, so the following is a description of the airports, then the most popular towns, followed by the "must see" attractions. Because most vacations are only 1-2 weeks, let's face, it there just isn't time to visit them all!
San Jose is the largest city and the capital of Costa Rica. It is home to the Juan Santamaría International Airport and where most arriving visitors first touch down. While not known as a major tourists destination and often described as not "pretty", it does have many nightspots and points of interest. If you enjoy learning about a country's culture/history, see the National Museum with its preColumbian artifacts and 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.
The second international airport is the Daniel Oduber International Airport in Liberia which is located in the northwestern province of Guanacaste. This airport opens up the popular beach destination along the coast. It's popularity and smaller size make tickets more expensive.
Don't miss the Arenal volcano! It's even large enough and hot enough to generate its own weather! It growls, explodes and real lava flows! Catch it at night in the rainy season and watch it generate its own lightning. Then, watch the lightning strike over the top of the volcano, illuminate a dark, cloudy night, and exposing the smoke from med-sized explosions. Very often, if you're on the right side of the volcano you can actually see flowing lava.
Update: The Arenal volcano is beautiful but stopped erupting in October of 2010.
Relax in the spring water heated from the volcano at the Tabacon or Baldi Hot Springs...what lush and beautiful spots! Yes, they are touristy, but there are so many different pools at both 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.
Venado Cave a real adventure a short drive from La Fortuna and budget friendly at only $20 per person.
An interesting town, known for its surfing and laid-back, it's the place to go for those wanting to get away from civilization, but not too far. It has a 1.5 kilometer stretch of beach perfect for a walk or run on the beach. In fact, one of the major reason this town is so interesting is that visitor's don't even need a car, everything is within easy walking distance. Some of the local residents don't even own cars! Imagine that!
Also, stiff competition and the desirability of living in Tamarindo have again proved the theory of the "Survival of the Best" and left standing are many outstanding restaurants, such as Carolina's and La Laguana Cocodrilo (not yet discovered), and there are many more! The longer you stay and the more people you meet, the more you'll get involved with the community, and feel like you've been somewhere.
It is has an international flavor with community-spirit. If you must, it is dotted with all-inclusive hotels, but try not to spend too much time inside a hotel, as there is plenty to do in town, and tour operators to take you to most of the the "must see" places in the northwestern portion of Costa Rica.
For those wanting to visit the volcanoes of Arenal or Rincon de la Vieja, it is a well-positioned hub location to keep driving time to a minimum, especially when landing in the Daniel Oduber International Airport in Liberia.
It is 4.5 hours from San Jose and Arenal. From Daniel Oduber it is only 1-hour and 1-hour more driving to get to the Rincon de la Vieja volcano.
Once there, it's the place to go to learn to surf and as a "jumping-off" points for the internationally famous surf spots such as:
Note: All of these places, including Tamarindo were featured in the surfing cult classic film, "Endless Summer II." In fact, Robert August, the two-time world champion that was featured in the film still lives there.
Also, there are several surrounding towns that visitors find to their liking, all a little smaller, but each with their own charm.
Manuel Antonio is a beautiful beach town featuring the Manuel Antonio Park on the Central West Coast. Easiest access if from the Juan Santamaria airport in San Jose. 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.
Arenal Volcano - Located in the Northern Central Mountain region - nearest towns Arenal, Fortuna, Monteverde
Located in Arenal which is nearby San Carlos Fortuna. See above... a don't miss!
Surfing and the beaches of Tamarindo - Located on the Northern Pacific coast - nearest towns Playa Grande, Flamingo Beach
A place to relax on the beach in a dry climate and visit great restaurants. It is only one-hour from the international airport in Liberia, 2-hours from Rincon del la Vieja volcano area, and a 4-hour drive to the international airport in San Jose. Surfer's only: it is a jumping off point for Witch's Rock, Ollie's Point, and Playa Negra. All-featured in "Endless Summer II."
Manuel Antonio National Park - Located on the Central Pacific coast - nearest towns Quepos, Jaco
Famous walking tours where you can see an abundance of plant and wildlife. Best of all, its located right next to the beautiful beach town of Manuel Antonio. Many find it a difficult choice when choosing between here and Tamarindo Beach. Tamarindo is closer to the Arenal area and Manuel Antonio is closer to the international airport in San Jose.
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.
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 Featuring smooth ride, with great animal viewing - howler monkeys, spider monkeys, small alligators, many birds, lizards, butterflies - you'll want to take your zoom lense camera
Zip Line Canopy Tours (You'll find a tour nearby most anywhere)
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 - Nearby the Arenal Volcano and San Carlos de Fortuna
The main reason to visit Monteverde is to visit 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
Orosi Valley: The valley is located in the province of Cartago. It is a deep valley with humid climate, surrounded by hills and lush vegetation, about 35 km southeast of the capital San José.
Study Spanish in Costa Rica: Many people choose to study Spanish during their time in Costa Rica because of the benefits that immersion has for learning a new language. There are a variety of schools to choose from and many combine Spanish classes with other activities to make your vacation full, fun, and meaningful. If you take classes at the start of your trip, you can use your new skills during the remainder of your time in Costa Rica.
Volunteer in Costa Rica: If you are interested in volunteering, there are a variety of ways to do so in Costa Rica. From building homes for the needy, to tutoring children, to helping save and protect wildlife, there is something for every volunteer.