Penyengat Island (Pulau Penyengat) sits just a few minutes by sampan from the Tanjung Pinang waterfront — the crossing costs almost nothing — and rewards the trip with a compact, walkable island packed with the remnants of the Riau-Lingga Sultanate that once controlled trade across this part of the archipelago.
The yellow Grand Mosque of the Sultan of Riau dominates the island's interior. Built in the mid-19th century, it is easily the most photographed building in the Riau Islands, its domes visible from the ferry as you approach. The royal tombs of the sultans and their consorts cluster around the mosque, some still draped in cloth by local devotees. Scattered further across the island are the crumbling walls of old palaces, guard towers, and a fort — most open to wander without charge.
The island has about 2,000 residents and you will be wandering through a living village as much as an archaeological site. Locals rent bicycles for a handful of rupiah; a circuit of the island takes an hour. The grave of Raja Ali Haji — 19th-century scholar and author of the first Malay grammar — is marked on most maps and is considered a place of pilgrimage for Malay literature scholars. Bring your own water; the island's stalls are limited.