Bora Bora is the eroded core of an extinct shield volcano: twin peaks, Mount Otemanu and Mount Pahia, rise from a shallow turquoise lagoon that is ringed by a barrier reef and scattered motu. Toggle the lagoon depth bands to see the color-coded shift from shallow to deeper water, and the motu markers to see the small sand-and-coral islets strung along the reef.
Published figures: Mount Otemanu about 727 m (2,385 ft), the highest point; Mount Pahia about 661 m (2,169 ft); lagoon area about 40 sq km; land area about 30 sq km; encircling barrier reef carrying scattered motu; Society Islands (Leeward group), French Polynesia.
Drag to orbit and scroll or pinch to zoom. Everything renders on your device with WebGL.
Bora Bora Lagoon 3D Explorer
This browser explorer shows Bora Bora as a cross-section: two rocky peaks, Mount Otemanu and Mount Pahia, rising from a shallow turquoise lagoon that is bounded by a raised barrier reef carrying small sand-and-coral motu, with darker open ocean beyond the reef.
Bora Bora is what is left of a much larger shield volcano. Millions of years ago the volcano was a tall, active island; as it went extinct and the seafloor beneath it slowly subsided, the outer slopes eroded away and sank below the waterline while a fringing coral reef kept growing upward at roughly the pace of the sinking, staying near the surface. What remains today is the eroded volcanic core (the twin peaks) standing inside a wide lagoon, ringed by the reef that grew around the original island's edge - a textbook example of the "almost atoll" stage of volcanic island subsidence that geologists have documented across many Pacific islands.
- Toggle lagoon depth bands to see the color-coded shift from shallow reef-side water to deeper mid-lagoon water
- Toggle motu markers to see the small sand-and-coral islets strung along the barrier reef
- Read peak heights, lagoon area, and formation history in the panel
- Drag to orbit, scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
- Your depth-band and motu-marker choices are saved in your browser, so the scene reopens the way you last left it
| Figure | Published value |
|---|---|
| Mount Otemanu | about 727 m (2,385 ft), the highest point |
| Mount Pahia | about 661 m (2,169 ft) |
| Lagoon area | about 40 sq km |
| Land area | about 30 sq km |
| Formation | eroded core of an extinct shield volcano, ringed by a barrier reef as the island subsided |
| Location | Society Islands (Leeward group), French Polynesia; main settlement Vaitape |
For another volcanic-island lagoon shaped by reef and subsidence, see the Great Blue Hole 3D Explorer, or for a different pair of named summits rising from one landform, the Mount Kilimanjaro 3D Explorer.
The twin-peak relief and its reef-ring motu markers are built and rendered on your own device with WebGL, so orbiting the lagoon and flipping the toggles stays smooth after the vendored three.js engine loads once (about 0.7 MB) and is cached for return visits.
Reading the reef and the peaks
Two toggles carry most of the teaching value here. The lagoon depth-band coloring maps the color-coded shift from shallow turquoise water near the reef to deeper blue water closer to the peaks, so the lagoon's shallow, gentle basin reads at a glance instead of as a flat description, and the motu markers pick out the small sand-and-coral islets that sit on top of the barrier reef ring, visible evidence of the reef's own growth around the sinking volcanic island. Drag to orbit, scroll to zoom, and your toggle choices are saved in browser storage so the scene reopens the way you last left it.
This is an educational approximation - the peak proportions, reef shape, and motu placement are schematic teaching cues, not a survey-grade bathymetric model.
Frequently Asked Questions
How tall are Bora Bora's peaks?
Mount Otemanu, the highest point, is about 727 m (2,385 ft). Mount Pahia, the second peak, is about 661 m (2,169 ft).
How did Bora Bora's lagoon and reef form?
Bora Bora is the eroded core of an extinct shield volcano. As the volcano went extinct and the seafloor beneath it slowly subsided, a fringing coral reef kept growing upward near the surface, leaving the twin peaks standing inside a lagoon ringed by that reef - the "almost atoll" stage of volcanic island subsidence.
How big is the lagoon?
About 40 sq km, larger than Bora Bora's own land area of about 30 sq km.
What are motu?
Motu are small sand-and-coral islets that sit on top of a barrier reef. Bora Bora's reef carries several scattered motu around its rim.
Where is Bora Bora?
In the Society Islands (Leeward group), French Polynesia, in the South Pacific. Its main settlement is Vaitape.
Is this a scientific bathymetric model?
No. It is an educational explorer using published figures - the peak proportions, reef shape, and motu placement are schematic teaching cues, not a survey-grade model.