A great hiking introduction comes with the first official trail route appearing at Highway 191's 10.2km marker. Big Tree Trail is just under a mile and classified as moderate difficulty because of some fairly steep sections making for uphill scrambles on the return. The path is paved and was one of the best maintained, including hand railings where needed.
Information placards are scattered along the trail's first half, detailing significance of various tree species thriving in the Tabonuco Forest below 2,000 feet. Farther off-trail, some of these protected, towering hardwoods date a 1,000 years old, outliving relatives that used to luxuriate the island before Spaniards arrived and began culling lowlands. Many of Old San Juan's original structures still stand strong 500 years later thanks to durable beams and planks, but it was construction of Spanish warships that prompted an export ban, perhaps sparing further deforestation.
For peace of mind, identify the Yagrumo Tree, which is found all over the forest and dominates this area. Excelling with dual-purpose thanks to rapid growth over a short-lived lifespan of 40 years, Yagrumos provide critical canopy cover, and their odd-shaped leaves carpet the forest floor trapping seeds and pods for germination. However, it's a long fall from top to bottom, and leaves come crashing through the dense vegetation with a startling Jurrasic Park-type rumble!
Lower elevations receive less than 100 inches of annual rainfall but can be inundated with ground runoff from higher levels. Sunken trails weave along hair-pin curves descending the mountain where looking down can be as fascinating as trapsing with head tilted upward and mouth agape. Exposed from top soil continually washing away, intricate root systems have entangled with vines forming artistic natural sculptures clandestine in the sea of green.
Nearing the halfway point, stillness is enlivened with sounds of water cascading down the mountain, signaling anticipation for seeing the grand finale. Thundering turned out to be only a small stream meandering down a rock course, I turned back feeling extremely cheated. Thankfully, the final, earlier missed trail marker pinpointed that this wasn't the marvel and intended course was resumed.
La Mina Falls is the ultimate destination for using this trail, and the roar is audible long before sight. The falls is the park's most substantial, regardless of rainfall, and small pool at the base is the only spot for dipping. Cool waters were nice for soaking feet, and a person could totally submerge himself in the shallowness with a little effort, but large underwater rocks make for tipsy wading. What the area excels in for beauty, it lacks in size and quickly fills up on weekends.
La Mina Trail embarks from behind the Palo Colorado Visitor's Center and is the other alternative for getting to La Mina Falls. This trail is barely over a mile and even steeper. To hike the full trail from either starting point is 2 miles. Also, factor another mile walk along Highway 191, which separates the trail head parking lots.