Culebra, Vieques and the Bio Bay

Off Puerto Rico's east coast lie the tranquil islands of Culebra and Vieques, the Spanish Virgin Islands, a slower, more idyllic world of striking beaches and clear turquoise water. Culebra is home to Flamenco Beach, regularly ranked among the most beautiful beaches on earth, a glorious curve of powder-white sand. Vieques, larger and wilder, roamed by free-ranging horses, harbours Mosquito Bay, the brightest bioluminescent bay in the world, where microscopic organisms make the water glow an ethereal electric blue when disturbed on a dark night, a magical experience.

What's there

• Flamenco Beach - Culebra's world-famous white-sand beach.
• Mosquito Bay - Vieques's glowing bioluminescent bay by night.
• The snorkelling - the reefs and clear turquoise water.
• The wild horses - the free-roaming horses of Vieques.

When to go

December to April, the dry season, for the best weather and calmest seas; the bioluminescent bay glows brightest on dark, moonless nights, so time a bio-bay tour away from the full moon. The islands are reached by ferry or small plane and reward a relaxed overnight rather than a rushed day trip.

Good to know

The islands are quiet and low-key, with limited facilities and sometimes unreliable ferries, so they suit relaxed travellers rather than those seeking resorts or nightlife; some areas still bear scars from hurricanes and Vieques's former use as a military range. Swimming is not allowed in the fragile bio bay.

Nearby

The main island's east coast at Fajardo is the ferry and flight gateway.