For over 400 years Arenal Volcano's forest-covered cone sat alone and silent on the edge of the San Carlos plains, exhibiting only a little fumarole activity in its single, dormant crater. In 1968 it erupted violently without warning, spewing molten rock and ash high into the sky, destroying the village of Pueblo Nuevo, killing 78 people, and forming three new craters.

It has been active ever since with more or less regular eruptions of lava and ash providing fiery demonstrations that draw curious onlookers from all parts of the world. Arenal's constant activity has covered the two lower craters on the western, rocky slope. Viewed from north or south its two remaining craters appear as twin peaks belching ash and rock.

Rich farming countryside, the flat lowland region that surrounds the majestic Arenal is the heartland of Costa Rica. The volcano towers over lush green pastures, and plantations of papaya and cassava. Rumblings, and occasional explosions, form the backdrop of the lives of these country people-(campesinos) who make their living from raising animals and crops.

Most dramatic at night, the 1,633-meter-high volcano can be seen from many vantage points near La Fortuna, the town in the province of Alajuela that is closest to the volcano, a winding four-hour drive from San Jose.

On clear nights, local couples and families pack a cooler and drive out from town to park their cars by the side of the road to watch the show of lights and fire. While a number of lodges and resorts in the area offer excellent views of the volcano, many visitors prefer to continue on past the hot springs to the national park an unpaved turnoff on the left, which also leads to the private Arenal Observatory. From here it is possible to hike four kilometers through part of the area devastated by the 1968 eruption.

Although at least one La Fortuna-based tour operator offers trips up Arenal, it is not advisable to climb the volcano. One tourist was killed and another burned in July 1988 when they hiked too near the crater. Their foolhardy trip also endangered the lives of the Costa Rican Red Cross, who rescued the body.

The area around Arenal Volcano offers a multitude of activities for adventure and nature lovers. Arenal Lake is a popular spot for wind surfers, fishermen and boaters. Fishing and windsurfing tournaments are annual events on this man-made lake created to provide hydroelectric energy. The lake is a 24-mile-long reservoir beginning at the foot of the volcano. The road around the lake-passable, but four-wheel drive recommended-is dotted with lodges and restaurants.

A major attraction has developed on the volcano's northwestern skirt where a hot river runs. Tabacon Resort has channeled part of the river's flow into several pools and a manicured tropical garden. This is a magnificent place to swim in a relaxing way to soothe muscles sore from horseback riding or hiking. In the shadow of Arenal while watching giant glowing boulders tumble down its slope.

Venado Caves, north of the lake, offer the adventurous an exciting journey underground. Visitors crawl, wade and climb through this dark, sometimes narrow 1.5-mile system of caves. Further north, near the Nicaragua border, is Caño Negro Wildlife Refuge. The nearly 2000-acre seasonal lake within the park attracts an abundance of waterfowl including roseate spoonbills, wood storks, anhingas and the seriously endangered jabiru stork.

Tourism-based around volcano watching, water sports and nature activities-is booming in the Arenal area, but has stayed on a small, family-owned scale. Active, low-cost sightseeing and adventure activities abound, most within a one-hour drive from the friendly town of La Fortuna. The majority are accessible by four-wheel drive, some by two-wheel drive, and all are daily destinations.