Sanggar Agung's roots stretch back to 1978, when a smaller temple called Kwang Kong Bio -- the Temple of Guan Gong -- was built about 500 meters south of the current site during the Moon Festival. That original structure was relocated three times over the following decades, each move bringing it closer to the shore. In 1999, the temple was officially established at its present location within the Pantai Ria amusement park, and given the Indonesian name Sanggar Agung, meaning "Great Hall." The Chinese name, Hong San Tang, translates to "Hall of Great Benevolence." Some of the deity figurines worshipped inside had already been venerated in the older temple for decades, carrying their accumulated prayers into the new space.

What makes Sanggar Agung architecturally distinctive is its position over the water. The temple extends out from the shoreline, its foundations submerged, so that worshippers walk across the sea to pray. This is not mere spectacle. Because the temple faces the open water, it has become a favored site for Chinese Indonesians to perform ancestral rites for cremated family members, releasing prayers across the waves. Flanking the entrance, a pair of Chinese lion statues embody the principle of yin and yang -- the female lion cradles a cub, symbolizing the nurturing force, while the male lion carries a ball, representing outward energy. The giant golden Phra Phrom statue, a Thai representation of the Hindu god Brahma, stands in its own courtyard nearby, its four faces gazing in the cardinal directions.

Sanggar Agung is formally a Tridharma temple, meaning it unifies the three teachings of Buddhism, Taoism, and Confucianism under one roof. But the reality inside is even more expansive. The temple houses separate altars for Mahayana and Theravada Buddhism, for Taoist deities like Tai Shang Lao Jun and Xuan Tian Shang Di, for the sea goddess Mazu, for Confucius, for the Eight Immortals, and for the Hindu deity Ganesha. Worshippers follow a prescribed route through the altars, beginning at the front of the temple where the Dragon God -- originally installed as an ornament before devotees began praying to it -- keeps watch over the sea. The temple employs and is maintained by people of various faiths, including Muslims and Christians, a practical expression of the religious pluralism that characterizes much of Indonesian spiritual life.

The 20-meter Guan Yin statue dominates the waterfront, facing outward toward the Java Sea as Nan Hai Guan Shi Yin Pu Sa -- Guan Yin Bodhisattva of the South Sea. The statue's scale and placement make it visible from considerable distance along the coast, a landmark for both worshippers and passing boats. Behind her, the temple's layered rooflines and ornate facades create a silhouette that is unmistakably Chinese against the tropical sky. Despite its origins as a place of worship, Sanggar Agung has become one of Surabaya's major tourist attractions, drawing visitors who come for the architecture, the ocean views, and the unusual experience of standing inside a temple surrounded on three sides by water. At sunset, when the light turns golden and the sea beneath the temple floor catches the last of it, the boundary between sacred space and natural wonder dissolves entirely.