Working for the turtles in Costa Rica - In Tortuguero, Costa Rica's own mini-Amazon, guests help scientists tag leatherback turtles for the Caribbean Conservation Corporation (www.cccturtle.org) while living in the research facility's basic (but beachside) accommodations.

Adventure outfitter in Costa Rica - Costa Rica Expeditions' multisport packages include zip-lines, rafting Class Four rapids, mountain biking. Or request a bespoke itinerary, customized to your most heart-racing extreme.

Taxis in Costa Rica - Taxis (usually painted red) are readily available throughout the country. Taking a four-wheel-drive taxi is always safer as roads are unpredictable; and hailing one on the street should be done only in San José and during daylight hours. It’s better to have your hotel staff arrange a taxi ride for you. Rates are metered and begin at around $1, with 50 cents added for each kilometer. Pay with small bills to avoid arguments with a driver who claims not to have change; if the driver says his meter is broken, agree on a fixed rate before you get in.