An aerial view of trees, the beach, and turquoise water in Fajardo, Puerto Rico - Javier Cruz Acosta/Shutterstock Teeming with the allure of tradition and modernity, San Juan, Puerto Rico's capital, ...

Bioluminescence is one of those natural phenomena that you simply have to see to believe. The idea of shores glowing with a glittering, blue-green light sounds like something out of a fever dream, but ...