It's hard to keep up with the number of aerial trams, zipline canopy tours, and ecotourism sites opening every year in Costa Rica. One of the consistent trends in this tiny Central American nation is that when a new entity becomes a success (such as the first zipline experience, introduced about 12 years ago), dozens of copy-cat entities soon spring up.
During my recent 10-week research trip for the seventh edition of Moon Costa Rica  (to be published in September 2009), I discovered many exciting new entrees.
Perhaps the most exciting is the Veragua Rainforest Research & Adventure Park , near Limón. The park is the keystone of a private reserve protecting 1,300 hectares of primary and secondary rainforest at Las Brisas del Veragua (the turn-off is at Liverpool, about 12 kilometers west of Limón; 4WD required).
This superb facility, which opened in autumn, combines many of the best elements that thrill visitors to a handful of other popular ecotourism sites in Costa Rica. Highlights include butterfly, snake, and frog exhibits (including a walk-through nocturnal frog garden with misters) linked by elevated boardwalks over the forest. An open-air tram through the canopy whisks you steeply down to the "Trail of the Giants" riverside trail (good for spotting poison-arrow frogs), which leads to a fabulous waterfall. Thoughtful education signage is a bonus.
This is an active research facility also, run in collaboration with INBio; you can watch biologists at work. Even the stylishly modern yet old-fashioned urinals offer forest views! The entrance fee includes a guided tour and lunch in a lovely open-air restaurant.
Oh, and there's a zipline canopy tour adjoining.
If heading to the Caribbean, don't miss this superb site.