To Sua Ocean Trench is one of Samoa’s most famous and breathtaking natural wonders. Located on the southern coast of Upolu island, its name literally translates to “Giant Swimming Hole.” It is a spectacular, 30-meter (98-foot) deep sinkhole that has formed from the collapse of an ancient lava tube. The trench is filled with crystal-clear, turquoise seawater, fed by an underground lava tube that connects it to the nearby Pacific Ocean. Surrounded by lush, immaculately maintained gardens, this stunning natural pool is a world-renowned destination for swimming, photography, and experiencing the unique volcanic geology of Samoa.

Name and Address

• Name: To Sua Ocean Trench.
• Address: Located in the village of Lotofaga, along the Main South Coast Road on the island of Upolu, Samoa.

How to Get There

The trench is a major landmark on Upolu and is a highlight of any trip along the south coast.

• By Car/Taxi (Recommended): This is the most convenient way to visit. The drive from the capital, Apia, takes approximately 1 to 1.5 hours via the scenic Cross Island Road. The entrance to the site is well-signposted from the Main South Coast Road. A small entrance fee (tala) is required, which goes to the local family that owns and maintains the site.
• By Bus: It is possible to take a local bus from Apia heading towards Lotofaga. You can ask the driver to drop you off at the entrance, which is a short walk from the main road.
• Guided Tours: To Sua is a staple of almost every full-day tour of Upolu Island. These tours provide hassle-free transportation and often combine the visit with other south coast attractions.

Landscape and Architecture

The “architecture” of To Sua is entirely natural—a dramatic geological formation set within a beautifully manicured landscape.

• The Trench: The main feature is the massive, near-perfectly circular sinkhole. Its steep, rocky walls are draped in lush green vines and foliage, creating a stunning contrast with the vibrant turquoise water below.
• The Ladder: Access into the trench is an adventure in itself. Visitors descend a steep, but sturdy, wooden ladder down to a small wooden platform at the water’s surface. This iconic ladder is a famous feature of the site.
• Lava Tube Connection: The trench is not a stagnant pool; it is connected to the ocean via an underwater lava tube. This allows for the constant circulation of fresh, clear seawater, and the water level rises and falls with the tide. Ropes are strung across the pool for swimmers to hold onto, especially when the current is strong.
• Surrounding Gardens and Coastline: The trench is set within beautifully maintained tropical gardens with traditional Samoan fales (huts) for relaxing and picnicking. A short coastal path leads from the gardens to a rugged lava field coastline with blowholes and rock pools, offering spectacular views of the ocean.

What Makes It Famous

To Sua Ocean Trench is world-famous for its surreal beauty and for offering one of the most unique and photogenic swimming experiences on the planet.

• A Perfect Natural Swimming Hole: Its primary claim to fame is its status as an idyllic, natural swimming pool. The combination of the deep, clear, brilliantly colored water and the lush, jungle-like setting makes it an unforgettable place to swim.
• The Iconic Ladder: The dramatic descent via the long wooden ladder is an iconic and thrilling part of the experience, and it is featured in countless travel photos and social media posts.
• Photogenic Beauty: To Sua is incredibly picturesque. The view from the rim looking down into the vibrant blue-green water surrounded by lush foliage is one of the most famous and sought-after images of the South Pacific.
• Geological Uniqueness: As a perfectly formed, ocean-fed sinkhole created by a collapsed lava tube, it is a spectacular and accessible example of the volcanic geology that shaped the Samoan islands.

Differences from Other Wonders

To Sua Ocean Trench offers an experience that is distinct from Samoa’s other natural attractions.

• Contained Swimming Hole vs. Open Beach: Unlike the open, expansive experience of Vavau Beach or Lalomanu Beach, To Sua is a contained, cavernous swimming hole. The experience is more intimate and dramatic, focused on the single, deep pool rather than a wide stretch of sand and sea.
• Interactive Swimming vs. Observational Waterfall: While Papapapaitai Falls is a magnificent waterfall to be viewed from a distance, To Sua is a completely interactive water feature. The entire purpose is to descend into it and experience the water.
• Geological Formation vs. Man-Made Sanctuary: The trench is a raw, natural geological formation. This contrasts with the Robert Louis Stevenson Museum, which is a historical, man-made structure, or even the Giant Clam Sanctuary, which is a community-managed conservation area. To Sua’s appeal lies in its untouched, natural formation.