Muara Besar Island

Muara Besar Island (Pulau Muara Besar, Abbrev: PMB) is an island in Mukim Serasa, Brunei-Muara District, Brunei. The island is essential for the Brunei–China relations due to its part in the Chinese Belt and Road Initiative. It can be noted that the island may be referred to Muara Island in older works.

A proposal for an 940 ha protection status to be implemented on the island. The island is home to migratory birds, shoebirds, primary forests and forest swamps.

Location and geography
The island is located within the Brunei Bay, in the south of the South China Sea. Administratively, it is part of Mukim Serasa of the Brunei-Muara District, Brunei. A mangrove forest is present on the inhabited island.

Early history
During the Battle of Brunei in World War II, United States Navy warship USS Willoughby (AGP-9) was relocated off Muara Island to which a newly established PT boat base on the island on 10 July 1945. The ship sat near the island until the Potsdam Declaration was signed on 15 August 1945. In 1988, it was recommended that 90 ha of the southeast end of the island to be protected.

Industrial park and PMB refinery
A Memorandum of Understanding (MoU) was signed in January 2008, in order to explore the construction of an export-focused industrial park. In 2011, the Ministry of Finance and Economy (MoFE) approved the Zhejiang Hengyi Group to establish the Hengyi Industries Sdn, and began to develop the island. The island is linked by the Pulau Muara Besar Bridge, which was completed in May 2018, and a deep sea container port.

The PMB Refinery operated by the Hengyi company within the PMB Industrial Park, was joined by two other Chinese companies (Zhejiang Hengyi Group and Damai Holdings). The industrial park took up a total land area of 955 hectares and are being used to produce petrochemical, oil and gas industries. The Phase 1 and 2 of the project were expected to be completed between late 2019 and 2023. The 2nd phase, which began construction on 25 September 2020, will be essential to Brunei's Gross Domestic Product (GDP).

Maritime yard project
Through a public–private partnership, Brunei is constructing its first comprehensive maritime vessel repair and decommissioning yard at Pulau Muara Besar. The goal is to establish a state-of-the-art facility that will serve the local customers, including Brunei Shell Petroleum, initially, and then the regional market, with maintenance, repair, and overhaul services for vessels in the region as well as asset decommissioning, materials recovery, and disposal services. Anson International has agreed to open the island as Brunei's first commercial integrated marine maintenance and decommissioning yard (MMDY) to first meet local needs before expanding into other regions.

The 16 ha integrated yard that will be built as part of the deal, which was signed on 29 June 2022, at the MoFE, will act as the anchor facility for the Brunei Darussalam Maritime Cluster (BDMC). The Adinin Group of Companies' Qaswa Holdings, a local lead partner in the joint venture, MoFE's Strategic Development Capital Fund, and two foreign companies—UK-based CessCon Decom for decommissioning and South Korea's Dongil Shipyard for marine maintenance—serve as lead technical partners for Anson. After a groundbreaking ceremony on 8 May 2024, the MMDY is expected to open for business by the third quarter of 2025.

Activities
There are a number of fish farms in the sheltered area between Pelumpong Spit and PMB.