Padang Lawas is not the kind of place you would expect to find temples. There are no major settlements, no cities, no obvious reason for sacred architecture on this flat, grassy plain. But geography provides the answer: the corridor between the Barisan Mountains and the northern highlands was a strategic route for people moving between Sumatra's east and west coasts. The flow of travelers, traders, and pilgrims through this passage between the 11th and 13th centuries CE left behind at least 25 brick shrines scattered across the plain. Candi Pulo, Candi Barumun, Candi Sipamutung, Candi Nagasaribu -- the names accumulate like way-stations on a forgotten road. The temples are believed to be linked to the Pannai Kingdom, a trading port on the Strait of Malacca coast operating within the Srivijayan mandala. Of all these shrines, only Candi Bahal has been fully restored. The rest remain in ruins, slowly being reclaimed by the plain.

Candi Bahal I, II, and III stand about 500 meters apart from one another, each enclosed within a perimeter wall roughly one meter thick and one meter tall. All three were built of red brick, their sculptures carved from sandstone. Eastern gates provide entrance into each compound, extended outward with low flanking walls. The main structure in each complex sits at the center. Rampant lions carved into the flanks of Bahal I bear a striking resemblance to carvings at Polonnaruwa, the 11th-century capital of Sri Lanka -- evidence that the builders drew on Buddhist artistic traditions spanning the Indian Ocean. The architecture also echoes Jabung temple in East Java, suggesting connections with the Majapahit world to the south. Restoration of Bahal I took place in 1977-1978 and again in 1982-1983; Bahal II followed in 1991-1992. The local name for the complex, "biaro" -- derived from vihara, or monastery -- hints at what these compounds may once have been: not just shrines, but places where monks lived and practiced.

The religion practiced at Padang Lawas was Vajrayana Buddhism, the tantric school that shaped spiritual life across much of maritime Southeast Asia during these centuries. No inscriptions found at the site directly name the kingdom that built these temples, but the religious practice matches that of Adityawarman, the 14th-century ruler who blended Srivijayan and Majapahit traditions. A bronze Buddha statue found at Si Pamatung in the nearby Barumun Tengah district reinforces the picture of a region steeped in Buddhist devotion. That Vajrayana Buddhism traveled from the monasteries of Bengal and Bihar to the plains of interior Sumatra speaks to the extraordinary reach of Indian Ocean trade networks -- not just of goods, but of ideas, scriptures, and spiritual lineages.

Unlike Java's celebrated temples -- Borobudur, Prambanan, the candis that fill guidebooks and draw millions -- the Padang Lawas temples have been largely neglected. The isolation that once made this corridor a useful passage now works against it: Bahal sits roughly 400 kilometers from Medan, about three hours by car from Padangsidempuan. Poor infrastructure and limited promotion have kept the complex off most tourist itineraries. This neglect is paradoxical. Candi Bahal is the largest temple complex in North Sumatra, a rare surviving example of Vajrayana Buddhist architecture in Indonesia, and physical evidence of the Srivijayan world's reach into Sumatra's interior. The 25 shrines of Padang Lawas represent a chapter of Indonesian history that predates the island empires most visitors know. They stand in their red brick on the broad plain, waiting for the travelers who once gave them purpose to find them again.