CENTRAL AMERICA We're proud to unveil the first three volumes in a brand-new series of full-color guides to the world's great adventures. Adventure travel is the fastest-growing trend in the travel industry today, and these exciting new guides offer a new approach to each destination. Each guide contains lively, personal accounts of 25 real adventures, combined with practical advice from the experts so you can plan a trip of your own no matter what your interest, skill level, or budget.      We'll tell you how to tackle each adventure on your own, or with the area's most noted outfitters. These are not catalogs of high-risk adrenaline sports, but guides to adventures within the reach of any reasonably fit person of any age and skill. We've also included a 64-page directory of other activities and outfitters in each region. Look for full-color photos throughout, plus regional and route maps, insider tips, seasonal calendars, and ideas for family travel ñ everything you need for a safe, worry-free adventure!