250px-Guanica_LightOctag­o­nal cylin­dri­cal mason­ry tow­er attached to a 1-sto­ry mason­ry keeper’s house; lantern removed. The tow­er and and keeper’s house are in ruins. The light­house was replaced by a buoy off­shore. This is a crit­i­cal­ly endan­gered light­house; the build­ing appears to be in dan­ger of col­lapse. Light­house Digest Dooms­day List. in May 2007, the Guáni­ca munic­i­pal­i­ty and the Depart­ment of Nat­ur­al Resources signed an agree­ment to restore the light­house and its sur­round­ings, but no work has begun yet. The light­house is with­in a com­mon­wealth nature reserve, El Bosque Seco (Guáni­ca Dry For­est). Located1.5 miles south of Guáni­ca, where the light­house for­mer­ly marked the east side of the entrance to the Bahía de Guáni­ca.

The Guani­ca light­house entered ser­vice in 1893. It was designed by José María Sainz and built on a plateau (Point Mese­ta) just east of the entrance to the Guani­ca har­bor, at the time one of the best and busiest in the island. The build­ing is 50 feet long by 28 feet wide. In con­trast to most light­hous­es, which fol­lowed a sober Neo­clas­sic style, this one (like the first Rin­con light­house) had an elab­o­rate brick cor­nice and para­pet. The rus­tic stone walls were cov­ered with white stuc­co that imi­tates the tex­ture of the base­board rocks.The coat of arms of the Corps of Road Engi­neers was placed on top of the entrance. The octag­o­nal tow­er is at the cen­ter of the build­ing and mea­sures 33 feet tall.

The sixth-order lens pro­ject­ed its light eight miles away. On July 25 1898, keep­er Robus­tiano Rivera spot­ted the invad­ing Amer­i­can forces and quick­ly trav­eled to Yau­co to inform the Span­ish author­i­ties. The light­house was used briefly as a hos­pi­tal dur­ing the short war. The build­ing was trans­ferred to the gov­ern­ment of Puer­to Rico in 1940 and the light was extin­guished in 1950, since then the light­house has dete­ri­o­rat­ed to the point that the only remains are the exte­ri­or walls, the tow­er (with its iron balustrade sur­pris­ing­ly in excel­lent con­di­tion) and a very small sec­tion of the roof. The cis­tern and well are near the build­ing. In May 2007, the Guani­ca munic­i­pal­i­ty and the Depart­ment of Nat­ur­al Resources signed an agree­ment to restore the light­house and its sur­round­ings, but work has not start­ed.