San Lucas Island
Island Former penal island off Costa Rica, now protected park
Island in Costa Rica’s Gulf of Nicoya that once housed a prison; visitors take guided hikes to ruins, watch seabirds and join boat trips from Puntarenas for wildlife and coastal views.
San Lucas Island (Isla San Lucas) lies off the Pacific coast of Costa Rica in Puntarenas Province and is best known for its former high-security prison. The island retains ruinous prison buildings that attract interest from visitors and historians.
Tours focus on the prison ruins, coastal trails, and opportunities to observe seabirds and other coastal wildlife. The shoreline and nearshore waters are also visited by recreational boaters and small-group tours from Puntarenas.
The island housed Costa Rica’s main island penitentiary from the late 19th century until the facility was closed in 1991, after which the site was left with substantial ruins of the prison infrastructure. Since closure the island has been managed for conservation and regulated visitation.
Isla San Lucas sits in the Gulf of Nicoya off the Pacific coast near the port city of Puntarenas in Puntarenas Province. Visitors travel to the island by boat from Puntarenas.
- Prison history: The island was used as Costa Rica's principal island prison from the late 19th century until its closure in 1991, and those prison structures remain as ruins.
- Access: Boat trips to the island depart from Puntarenas and are the usual way visitors reach the island for tours and wildlife observation.
What to See #
- Prison ruins: The former penal complex occupies visible ruins of cell blocks and support buildings; visitors can tour these remains on guided trips to learn about the island's penal history.
How to Get to San Lucas Island #
Day trips and guided tours depart from Puntarenas; the boat ride to the island takes roughly 45-90 minutes depending on the vessel. Tours typically include a guided walk through the former prison grounds and wildlife viewing; booking in advance is recommended.
Tips for Visiting San Lucas Island #
- Book a guided tour from Puntarenas or nearby tourist operators-trips often include ranger-led walks of the former prison area.
- Wear a hat and strong sunscreen-the island is exposed with limited shade near ruins.
- Respect restricted zones: parts of the former prison complex and wildlife areas may be off-limits for conservation reasons.
Best Time to Visit San Lucas Island #
Best visited in Costa Rica's dry season (December-April) for reliable boat transfers and clearer walking conditions.
Weather & Climate near San Lucas Island #
Tropical climate with consistently warm temperatures year-round. Temperatures range from 21°C to 34°C. Abundant rainfall (1722 mm/year), wettest in September with a pronounced dry season.
January
January is warm with highs of 32°C and lows of 21°C. The driest month with just 3 mm.
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February
February is warm with highs of 32°C and lows of 21°C. The driest month with just 3 mm.
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March
March is warm with highs of 33°C and lows of 22°C. Almost no rain.
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April
April is the hottest month with highs of 34°C and lows of 22°C. Moderate rainfall (42 mm).
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May
May is warm with highs of 32°C and lows of 22°C. Heavy rain (212 mm).
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June
June is warm with highs of 31°C and lows of 22°C. Heavy rain (319 mm).
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July
July is warm with highs of 31°C and lows of 22°C. Significant rainfall (132 mm).
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August
August is warm with highs of 31°C and lows of 21°C. Significant rainfall (198 mm).
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September
September is warm with highs of 31°C and lows of 21°C. The wettest month with heavy rain (370 mm).
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October
October is warm with highs of 30°C and lows of 21°C. Heavy rain (358 mm).
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November
November is warm with highs of 30°C and lows of 21°C. Moderate rainfall (69 mm).
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December
December is warm with highs of 31°C and lows of 21°C. Almost no rain.
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