The Guanica State Forest, or Bosque Estatal de Guanica, is the largest remaining tract of subtropical dry coastal forest in the world and a UNESCO Biosphere Reserve. Around 10,000 acres of cactus, gnarled trees, and limestone outcrops cover the headlands south and east of the town. Despite the spiky look, it is full of life: more than 700 plant species, roughly 100 bird species, and a healthy population of endemic Puerto Rican lizards.
The forest is laced with around 36 miles of trails, ranging from short scrambles to longer routes along the coast. The Ballena Trail and Fuerte Caprón Trail are the popular options — both lead to viewpoints over the Caribbean. Bring more water than you think you need; shade is scarce and temperatures climb fast. Early morning is best, both for birds and to beat the heat.