A Lake Born from Fire

Nestled within the vast caldera of Mount Rinjani at an altitude of approximately 2,000 metres, Segara Anak — meaning "Child of the Sea" in the Sasak language — is one of Indonesia's most breathtaking natural features. This crescent-shaped crater lake stretches over 6 kilometres in width and plunges to depths of more than 200 metres. It was formed by the collapse of a volcanic caldera thousands of years ago and continues to evolve, with the young volcanic cone of Gunung Baru ("New Mountain") rising from its waters and still actively erupting.

But for the people of Lombok and Bali, Segara Anak is far more than geology — it is a living spiritual site of profound importance.

Sacred to the Sasak People

The indigenous Sasak people of Lombok have revered Mount Rinjani and Segara Anak for centuries. In Sasak cosmology, Rinjani is considered the abode of the spirits of ancestors and deities. The mountain is called Gunung Rinjani but also referred to by its sacred name, Sajang, in certain ritual contexts.

Segara Anak is the focal point of an annual Sasak ceremony known as Pekelem, in which offerings are cast into the lake to honour the spirits residing within the mountain. Participants believe that these offerings maintain harmony between the human world and the spirit world, ensuring good harvests, health, and protection for the communities of Lombok.

The hot springs that feed into Segara Anak — particularly those at Aiq Kalaq — are considered to have curative properties. Local pilgrims bathe in these waters seeking healing from illness and spiritual purification.

A Pilgrimage Site for Balinese Hindus

Lombok's Balinese Hindu community holds Rinjani and Segara Anak in equally high regard. For Balinese Hindus, the mountain is one of the most sacred peaks in the Indonesian archipelago, linked to Gunung Agung in Bali as a complementary spiritual axis.

During Purnama Sasih Kapat (the full moon of the fourth Balinese month), Balinese Hindu pilgrims make the arduous climb to Segara Anak to perform melasti — a purification ceremony — and cast offerings of flowers, fruit, and jewellery into the lake. This pilgrimage, known as Pujawali, draws devotees from across Lombok and sometimes from Bali itself.

Respect on the Mountain: What Trekkers Should Know

As a trekker visiting Segara Anak and the Rinjani caldera, it is essential to approach these spaces with cultural sensitivity and respect.

  • Do not disturb offerings. You may encounter flower arrangements, incense, or other ceremonial objects near the lake. Leave them untouched.
  • Ask before photographing pilgrims. People conducting religious ceremonies deserve privacy and respect.
  • Avoid loud behaviour near the lake and hot spring areas, which are considered sacred ground.
  • Dress modestly if you are in areas where ceremonies are taking place.
  • Keep the lake clean. Littering in or near Segara Anak is both illegal and deeply disrespectful to the communities for whom this water is sacred.

The Meeting of Worlds

What makes Segara Anak truly extraordinary is how it serves as a meeting point — of tectonic forces and human faith, of different religions and traditions, and of the earthly and the divine. Trekkers who arrive at the crater rim at dawn and look down upon the still, turquoise waters below often describe a sense of awe that transcends the physical achievement of the climb. Perhaps that is exactly what generations of pilgrims have felt before them.