GETTING THERE: Eastern Airlines offers good connections from Washington to San Jose' via Miami; round-trip fare is $551 weekdays, $581 weekends, with 14-day advance booking. You can leave in the morning and arrive in the Costa Rican capital in midafternoon, or leave in early afternoon and arrive in midevening.

By changing carriers in Miami, you can also fly nonstop to San Jose' on Costa Rica's LACSA; or on El Salvador's TACA, with a stop in Belize, a flight over part of Honduras and stops in San Salvador and Managua.

WHAT TO DO: The Caribbean coast "jungle tour" is run once or twice a week, usually leaving San Jose' on Saturdays and Tuesdays. The minimum group size is eight persons, so you may need some flexibility in scheduling. A minimum of four must plan ahead to spend the extra night watching the turtles in season.

You can write for reservations to Rio Colorado Lodge, P.O. Box 5094, San Jose', Costa Rica, or direct-dial (506) 32-40-63 and make all arrangements in English -- no deposit is required.

In addition to the jungle tour, there are beach resorts south of Limo'n on the Caribbean coast and on the Pacific coast. The Nicoya Peninsula is reputed to have some of the best beaches.

Costa Rica is a crossroads of major flyways and a birder's paradise. The best spot is Monteverde, about a four-hour drive west and then north on the Pan American Highway from San Jose', an unpaved road into the rain forest steep enough that a jeep is recommended. Hotel de Montana in Monteverde can arrange expert guides.

But one can also get a good sense of Costa Rica's natural splendors in day trips from San Jose' to Irazu' volcano, to the old capital of Cartago and the Poas volcano, or to craft areas like Alajuela and Sarchi. And there are churches and museums to visit in San Jose' itself, and a lively night life.

WHERE TO STAY: The Irazu', halfway to downtown on the eight-mile road from the airport, and the Corobici, on the edge of downtown, are both luxury-class hotels under common ownership. Rates are $85 and up per night double. The Europa is a downtown first-class hotel with a small swimming pool and excellent dining room. It has the feel of an old continental hotel and charges $50 double.

On the eastern edge of downtown, near the university, is the Bougainvillea at $40 double. And there are dozens of inexpensive pensions -- spartan but clean -- most with private baths, for about $10 a night double, plus a half-dozen apartotels (with kitchens) at $25 to $40 double.

WHERE TO EAT: In San Jose', the Lobster Inn serves fine seafood for $25 and up for a full dinner for one with drinks or wine; Los Antojitos is a comparable restaurant specializing in beef dishes. There are also Chinese, French and Italian restaurants in San Jose' at prices ranging from $10 to $25 per person for a full meal. Most guidebooks list several good but unpretentious local eateries where $5 will get you a good meal, especially at midday: Cafe Mallorquina, Corona de Oro, El Caudil.

LANGUAGE: Tourist Spanish (meaning the bare minimum) is useful but not absolutely necessary in San Jose'; English-speaking people are fewer in the countryside, except on the Caribbean coast, where almost everyone is bilingual.

WHEN TO GO: The dry season is November through April; the heaviest rains fall in May and October, but several hours of afternoon rain are standard all summer. Turtles lay eggs from August through mid-October, hatch September through December. Fishing is good year-round. -- Don O. Noel Jr.