Labuan Cermin

Geophysical Uniqueness: The Two-Taste Phenomenon

The primary characteristic that makes Labuan Cermin so special is its layered water structure. The lake has a depth of approximately 4 to 5 meters, with its surface consisting of cool, fresh freshwater, while at its base lies a layer of warm, denser saltwater.

This phenomenon occurs due to the intrusion of seawater through underground fissures directly connected to the Sulawesi Sea, while its surface is supplied by karst mountain springs in the surrounding area. Astonishingly, these two layers are separated by a thin layer that appears like clouds or mist within the water (halocline), creating an extraordinary optical illusion. The water's clarity is extreme; boats floating on its surface appear to be hovering in the air because their reflections fall precisely on the rocky and white sandy bottom of the lake.

Unique Ecosystem and Biodiversity

The difference in salinity (salt content) within the same body of water gives rise to a rare biodiversity. At Labuan Cermin, visitors can witness the coexistence of freshwater and marine biota. In the upper layer, freshwater fish swim freely, while just a few tens of centimeters below, there are coral fish and other marine organisms.

The lake's edges are surrounded by dense tropical rainforests and majestic karst cliffs. Large trees with roots extending into the water provide shelter for various local fauna. The chirping of hornbills and occasional sightings of primates on tree branches add to the magical and ancient feel of this destination. The forests around Labuan Cermin function as a natural water catchment area, maintaining the lake's water quality and clarity throughout the year.

Outdoor Experiences and Activities

Labuan Cermin offers a profound sensory experience for nature lovers. The main activities that must be done are swimming and snorkeling. When diving, you will feel the sensation of a drastic temperature change as you move from the freshwater layer to the saltwater. The underwater visibility is exceptionally clear, allowing you to see the detailed textures of submerged wood at the lake's bottom and small rock formations with great detail.

For those who prefer to stay dry, renting a wooden boat from local fishermen is the best option. From the boat, the water's clarity allows you to see all the way to the lakebed without any aids. Taking photos from certain angles will produce images of boats that appear to be "flying." Additionally, exploring the forests around the lake via light trekking trails is also an attraction for nature photographers who want to capture the beauty of Kalimantan's flora and fauna.

Best Visiting Times and Seasonal Variations

To get the best visualization of this "mirror" phenomenon, the timing of your visit is crucial. The best time is between 10:00 AM and 1:00 PM WITA (Central Indonesian Time). During these hours, the sun is directly overhead and can penetrate to the lakebed, creating maximum light reflection and clarifying the boundary between the two water layers.

Seasonally, the best time to visit is during the dry season (May to September). During the rainy season, the flow of freshwater from mountain springs increases drastically, sometimes carrying a small amount of soil sediment, which slightly reduces the water's clarity, although it remains much clearer than in typical lakes.

Conservation Efforts and Environmental Protection

As an ecologically sensitive area, Labuan Cermin is under the supervision of the local community and regional government. Awareness of the importance of maintaining water purity is very high. Visitors are strictly prohibited from using chemical products such as soap or shampoo while swimming in the lake. Furthermore, the use of motorboats is regulated to prevent water pollution from fuel spills and to avoid disturbing the tranquility of the surrounding animal habitats.

The presence of karst forests around the area is also protected to ensure the water cycle is maintained. Without healthy forests, the springs supplying Labuan Cermin's freshwater layer could dry up, which would disrupt the two-taste balance that is its main characteristic.

Accessibility and Supporting Facilities

Although its location is quite remote, the facilities at Labuan Cermin are adequate for tourists. There is a well-maintained wooden pier, rental services for snorkeling gear, life jackets, and ferry boats. Around the main parking area, there are local eateries serving typical Berau cuisine, restrooms, and changing rooms.

Access to Labuan Cermin requires a rather long journey but is well worth it. From the center of Berau Regency (Tanjung Redeb), the land journey takes about 6 to 7 hours, traversing roads with views of forests and plantations. Upon arrival in Biduk-Biduk Village, visitors must rent a small motorboat from the pier for a journey of about 15 minutes along a calm river estuary before finally reaching the hidden entrance of Labuan Cermin.

Labuan Cermin is more than just a tourist spot; it is a reminder of nature's fragile yet extraordinary wonders. Its existence challenges us to continue preserving Kalimantan's forests so that future generations can still see the reflection of the sky on the surface of this tranquil "glass lake."