Una Una
Volcanic island with black sand, active crater, and the archipelago's best diving.
Una Una is a 146-square-kilometer volcanic island dominated by Mount Colo, an active 500-meter volcano with a 2km-wide caldera. The 1983 eruption killed most of the population and buried the island in ash, but fertile volcanic soil now supports dense coconut groves and volcanic nutrients have enriched the surrounding reefs. Fewer than 2,000 residents now live in villages clustered along the eastern coastline. The island offers world-class diving with 30-40m visibility, black sand beaches, and the chance to trek an active volcano.
- Best timing: Dedicated multi-day stop for diving and volcano trekking.
- Suggested stay: 2-3 days.
Why it matters
- Active volcano with accessible 2km-wide caldera — rare opportunity to trek a live volcanic crater.
- Consistently rated the best diving in the Togeans — sites like Apollo, Pinnacle, and Menara with 30-40m visibility.
- Black volcanic sand beaches contrasting with turquoise water and lush post-eruption vegetation.
Highlights
Mount Colo volcano trek
Hike the 500-meter volcano to reach the 2km-wide caldera formed by the 1983 eruption. The crater floor is covered in vegetation, volcanic steam vents still release heat, and views stretch across the entire archipelago. The trail climbs through coconut groves growing in fertile volcanic soil.
2km-wide calderaWorld-class dive sites
Sites like Apollo, Pinnacle, and Menara offer 30-40 meter visibility with massive corals, giant sponges, barracuda schools, trevally, reef sharks, and turtles. Volcanic nutrients from the 1983 eruption have enriched the reefs, creating exceptional coral health and fish density unmatched elsewhere in the Togeans.
30-40m visibilityEastern coastline villages
Fewer than 2,000 residents live in villages clustered along the eastern coast where black volcanic sand meets the water. Mosques, small ports, houses rebuilt after the 1983 eruption, and paths winding through coconut groves. No roads connect settlements — movement is by foot along coastal trails or by boat.
Eastern coast villagesPractical notes
- Volcano: Active 500m peak with 2km-wide caldera accessible by guided trek. Volcanic steam still vents.
- Diving: Best in the Togeans — 30-40m visibility at Apollo, Pinnacle, Menara sites. Book dive resorts in advance.
- Beaches: Black volcanic sand that heats intensely in sun. Bring sandals for beach walks.
- Villages: Under 2,000 residents clustered on eastern coast. No roads — movement by coastal trails or boat. Post-1983 recovery ongoing.
Ready to see it for yourself?
Our cruises run from Luwuk through the Togean archipelago. Check the departure schedule, or message us and we'll help you pick the trip that fits.