El Boquerón (San Juan, Puerto Rico)

This body of water contains coral reef and habitats important to plant and animal life; it is part of the bigger San Juan Bay National Estuary.

As the natural border between the original settlement of San Juan and the mainland of Puerto Rico, El Boquerón was a critical strategic point throughout the history of the city.

[3] Numerous bridges crossed it throughout the history, most of which would be burned down during British and Dutch invasions.

[5] The rock used to be so well known that it (and its surrounding coral reef) was declared a cultural and natural landmark in the year 2000.

The Piedra del Perro formation stood until 2016 when it was completely destroyed by strong waves.