Muzium Negeri Terengganu – Kota Lama Duyong – Provides historical and architectural details about the fort. Kota Lama Duyong at Terengganu Museum official site
Heritage Malaysia – Pulau Duyung – Background on the island, its name origin, and heritage significance. Pulau Duyung (HeritageMalaysia.my)
Wikipedia — Duyong Old Fort – Information on the fort’s history, architecture, and restoration. Duyong Old Fort (Wikipedia)
Penang Travel Tips — Pulau Duyong and Kota Lama Duyong – Additional background about the island and its heritage buildings. Pulau Duyong & Kota Lama Duyong guide
VIPMalaysia.com – Kota Lama Duyong – Overview of the fort with architectural highlights and visitor information. Kota Lama Duyong at VIPMalaysia