Guanica Dry Forest

El Yunque gets the rain and the visitors; Guanica gets the sun and the rarities. This UNESCO-designated biosphere reserve on the arid south coast protects one of the world's best-surviving subtropical dry forests - a landscape of columnar cactus, gnarled hardwoods, thorny scrub and limestone that supports an extraordinary concentration of endemic species, including most of Puerto Rico's remaining native bird species and the tiny Puerto Rican nightjar, once thought extinct. Trails run from the forest road down to the coast, where mangrove-backed coves and clear snorkelling water make a natural end to a hot walk.

What you actually see

• The Ballena trail - the classic route through cactus forest to the coast.
• Coastal coves - snorkelling stops where the trails reach the sea.
• Endemic birdlife - nightjars, todies and other species found nowhere else.
• The dry forest structure - cactus and thorn scrub unlike anywhere else on the island.

When to go

The cooler dry months from December to April make walking bearable and coincide with easier birdwatching. Start early in any season - by late morning the limestone radiates heat and the trails become punishing. Birders should aim for dawn.

Honest expectations

There is essentially no shade and no water on the trails, and the heat is the real hazard here rather than the terrain - carry far more water than a similar-length walk elsewhere would need. Trail markings are variable and the network is bigger than it first appears; take a map or track your route. Sturdy shoes matter as much for the thorns as for the rocks.

Nearby

Gilligan's Island cay offshore, La Parguera's bio bay and the Ponce museums to the east.