Aerial view of Casy islet in Prony Bay, Great South of New Caledonia.Casy islet in New Caledonia
©Casy islet in New Caledonia|Oneye Production

Casy islet

in Mont-Dore
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Huddled off the southern tip of New Caledonia, Casy Islet stands out as a precious jewel in the Great South. Paying homage to Admiral Casy in 1854, this islet, once inhabited, now hosts remnants from the penal colony era, concealed beneath thriving vegetation. With its exceptional biodiversity, the islet exudes an enchanting allure, creating a sense of solitude and tranquillity. Whether you choose to stroll, snorkel, dive, or simply unwind, Casy Islet beckons with opportunities to revel in the island’s rich tapestry of nature and history.

To get to Islet Casy, you’ll need to take a water cab from the Baie de Somme, in the Great South. From Nouméa, allow 1h15 to reach the bay. You’ll take the RP1 provincial road towards Prony and pass through the Mont-Dore. There’s no public transport to drop you off at the pier, so renting a car is essential. Remember to book the taxi-boat trip in advance and arrange your schedule with your driver.

  • There is a fee for taxi-boat transfers, make sure to book in advance with Casy Express.
  • You may spot some whales from mid-July to mid-September during your boat crossing.
  • You can camp on site but there are no foundations, so you’ll need to bring your own equipment.
Top 5 things to do on Casy islet

1. Swim with turtles

Casy islet beachCasy islet beach
©Casy islet beach|Oneye Production

    Classified as a nature reserve, Casy Islet reveals remarkable treasures of flora and fauna that captivate every visitor! Venture beyond the shoreline, and you’ll witness the enchanting sight of turtles gracefully emerging in the clear waters. Snorkelling enthusiasts, equipped with a mask, fins, and snorkel, often have the delightful opportunity to swim alongside these majestic sea turtles!

    2. Take the hiking trail

    Hiking trail of Casy isletHiking trail of Casy islet
    ©Hiking trail of Casy islet|Oneye Production
    Aerial view of Prony Bay from the top of Casy islet, in New Caledonia's Grand Sud region.Casy islet & Prony Bay
    ©Casy islet & Prony Bay|Oneye Production

      Embark on the longest trail on Casy Islet—the Grand Tour, spanning 3.3 kilometres and requiring approximately 1 hour and 30 minutes to complete. Complemented by the shorter Cycas Loop (1.8 km) and Cemetery Loop (0.8 km), this hike unveils the vestiges of the penal colony alongside the island’s diverse and vibrant nature. Your journey will lead you to historical sites such as the ancient well from the penal colony era and a cemetery adorned with shells, home to several graves. Traverse through cycad and araucaria forests, uncover charming beaches with panoramic views, and ascend to the island’s highest point (45 metres above sea level) for a breathtaking vista, gazing towards Cap N’Dua in the distance.

      3. Admire the lush vegetation

      Admire the columnar pines of Casy isletColumnar pines of Casy islet
      ©Columnar pines of Casy islet|Bsera
        Casy islet in the Great SouthCasy islet in the Great South
        ©Casy islet in the Great South|Anaëlle Chretien & Steven Lequertier

          Located close to the Aiguille de Prony (Prony’s Needle), this islet in the Great South unveils a natural treasure trove, boasting remarkable biodiversity with an astounding plant endemism rate exceeding 80%. As you traverse the islet, the towering banyan trees leave a lasting impression, while colonial pine forests coexist harmoniously with cycads and ferns. The island is a haven for botanical enthusiasts, showcasing a wondrous array, including seven varieties of orchids and over 60 wood species. In this untouched wilderness, surrounded by the immersive beauty of nature, you’ll truly sense the feeling of being at the end of the world.

          4. Follow in the footsteps of the past

          Discover the history of Casy isletDiscover the history of Casy islet
          ©Discover the history of Casy islet|Oneye Production

            Casy islet, though uninhabited today, holds a rich history, once serving as a home to Ouen Island tribe members, residents of the Prony prison camp, and later transforming into a hotel. Similar to the village of Prony, Casy islet has witnessed diverse phases of existence. Initially, Ouen islet tribes cultivated their vegetable gardens on Casy. Subsequently, in 1869, Prony prison camp employees settled there, engaging in agriculture and sheep farming to sustain the camp. The forest was actively utilised until 1911. Solely the family of Jean Alric, head of forestry and commander of the Prony prison camp, continued to reside there. From 1995 to 2004, the islet housed a hotel catering to a few tourists before its eventual abandonment. Along the main path of the islet, interpretative panels offer glimpses into the bygone eras and the erstwhile life on this now-deserted islet.

            5. Take a guided tour of the Somme Bay

            Numerous service providers in the Great South provide guided boat excursions to the thermal springs of Prony or Casy Islet. Some even offer the option to borrow a canoe for a self-guided exploration on the water. Additionally, during the whale-watching season from July to September, there are opportunities to select a whale-watching excursion that incorporates a stop at Casy Islet for a delightful picnic experience.

            Kayaking in Baie du Carenage, Grand SudKayaking in Baie du Carenage, Grand Sud
            ©Kayaking in Baie du Carenage, Grand Sud|Oneye Production / NCT
              Bathing at the Prony hot springs in New Caledonia.Bathing at the Prony hot springs
              ©Bathing at the Prony hot springs|Oneye Production
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