At the far west of the island are the ruins of an impressive stone fort, built by the sultan Raja Haji in the 18th century to fend off Dutch attacks. Ironically, the cannons you see here are Dutch made. Raja Haji, incidentally, was the author of the first Malay grammar book, a reminder that this island was once a hotbed of intellectual and religious minds, and at one time was home to more than 9,000 people.