The Grand Mosque of the Sultan of Riau (Masjid Raya Sultan Riau) stands at the centre of Penyengat Island in a brilliant yellow that makes it visible from the Tanjung Pinang waterfront. It is the most architecturally distinguished building in the Riau Islands and one of the oldest mosques in Indonesia still in regular use.
The main prayer hall can accommodate several hundred worshippers and is open to respectful visitors outside prayer times. The interior is cool and dimly lit, with calligraphy panels and old chandeliers. The surrounding complex includes the royal cemetery where sultans and consorts of the Riau-Lingga Sultanate are buried, many of the graves topped with white and yellow fabric. The approach from the landing dock passes through the village and gives a good sense of how tightly integrated the mosque is with the island's daily life.