Bioluminescent Mosquito Bay (Vieques)

#1 in Best Things To Do in Puerto Rico
Bioluminescent Mosquito Bay (Vieques) picture
Todd Van Hoosear/Flickr

Key Info

Price & Hours

Prices vary by tour company
Tour times vary by company


Beaches Type
1 to 2 hours Time to Spend


  • 4.5Value
  • 0.0Food Scene
  • 5.0Atmosphere

This south Vieques beach might not sound like much, but it's one of travelers' favorite experiences in Puerto Rico. During the day, Bioluminescent Mosquito Bay is your stereotypical Caribbean hideout but at night, the waters emit a blue glow from the organisms, called dinoflagellates, that live there. More than 600,000 bioluminescent dinoflagellates live in each gallon of bay water, and recent travelers have been amazed by just how much visibility these tiny creatures provide.

Avoid visiting the bay during a full moon; the microorganisms aren't as visible then. Also aim for a quiet approach. Recent travelers recommended going out in a kayak to get the full effect of the glow and to prevent disturbing the dinoflagellates.

Though you can visit Mosquito Bay unaccompanied, visitors suggest you spring for a guided tour of the area. Tours operate nightly and cost approximately $60 per person, depending on the company you book. In addition, do not wear bug spray that contains DEET, as it could harm the microorganisms in the bay.

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Time to Spend
#2 Old San Juan

Viejo San Juan is home to a variety of top attractions, including El Morro, Castillo San Cristóbal and Calle del Cristo. It's here you'll find Calle de la Fortaleza, which once held the city's famous umbrella installation but is now adorned with a massive Puerto Rican flag. While most people do take advantage of seeing the historic and iconic sights, many also visit Old San Juan just to experience the area. Numerous travelers encourage others to walk the cobblestone streets to view the historic, colorful architecture and experience the vibrant culture. No need to leave for lunch, this section of town is bursting with street vendors and restaurants ready to satiate your appetite. At night, the city comes alive and is filled with a bustling nightlife known for its drinks and dancing.

For optimal strolling, past visitors recommended seeing the area early in the morning before tourists wake up and vacationers disembark from their cruise ships (the cruise port is at the base of Old San Juan). Should your feet get tired, you can hop on the free trolley that operates throughout this part of town; however, know that it can run infrequently. You can visit Viejo San Juan 24 hours a day, but know that individual bars, shops and restaurants operate their own hours.

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