What to see
As far as Latin American capital cities go, San Jose is relatively small. There are some interesting museums, art galleries and shops, however, it does not warrant staying longer than a couple of nights. The surrounding Central Valley, however, offers plenty to see, including coffee plantations, the rainforest of the Braulio Carrillo National Park, and the crater lake and dwarf cloud forest of the Poas volcano.
On the northern Caribbean coast is the Tortuguero National Park, a network of waterways in thick jungle. From June to September large populations of Leatherback turtles nest on the beaches. Although this is an obvious main highlight of the region, outside of this time there is still an abundance of wildlife to be seen, either by easy hikes or leisurely boat trips along the canals in small motorised canoes. Monkeys, caimans, parrots and iguana are all frequently seen.
North of San Jose is the cloud forest of Monteverde. Only accessible by long drives on bumpy unpaved roads, the locals’ ineffective way of minimising the amount of tourists coming to the reserve, Monteverde offers a profusion of plant life, butterflies, insects and birds, as well as canopy walkways. Smaller quieter reserves and areas can also be visited, off the beaten track. The best way to appreciate the cloud forest is to walk along the trails with your guide and a pair of binoculars. These areas are fantastic places to spot elusive quetzals. 
Arenal Volcano National Park should not be missed on any tour of Costa Rica. The volcano is one of the country’s most active and visitors come to relax in the many hot springs, see the lava fields, explore canopy walkways or take trips to the Caño Negro / Rio Frio wetlands. Further off the beaten track are the Tenorio Volcano National Park and Rincon de la Vieja National Park - areas with volcanic activity, hot springs, rainforest and dry forest, as well as the beautiful turquoise Celeste river.
The beaches of Guanacaste and the Nicoya peninsula are some of the finest in Costa Rica and there are different hotels to suit all budgets and styles, from boutique properties to larger resorts. Between December and April it is possible to visit the beaches near Tamarindo or Ostional during the night on a guided tour to watch the hatching of baby turtles. Further south, the beaches of the central Pacific coastline are perfect for combining exploration and relaxation, as well as opportunities to see wildlife in national parks such as Manuel Antonio and the Ballena Marine National Park. 
In the far south-west of the country lies the Osa peninsula, home to remote beaches and the Corcovado National Park, where the dense rainforest protects an incredible diversity of flora and fauna. Jungle lodges here range from simple and comfortable to rustic luxury.