A:Pacaya is a Central American classic. Just outside Antigua, it’s a short, steep climb, generally busy with tour groups and touts offering horse rides to the top. But never mind the crowds and commerce: The two-mile trail will get your blood pumping, and the last stretch covers some more challenging volcanic terrain. The highlight is the trail’s proximity to red-hot, active lava flows. Get into the tourist-trap spirit and toast a marshmallow or two at the top.