Natural harbour in the context of "Sea wall"

Mumbai (/mʊmˈbaɪ/ muum-BY; Marathi: Mumbaī, pronounced [ˈmumbəi] ), also known as Bombay (/bɒmˈbeɪ/ bom-BAY; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12.5 million (1.25 crore). Mumbai is the centre of the Mumbai Metropolitan Region, which is among the most populous metropolitan areas in the world with a population of over 23 million (2.3 crore). Mumbai lies on the Konkan coast on the west coast of India and has a deep natural harbour. In 2008, Mumbai was named an alpha world city. Mumbai has the highest number of billionaires out of any city in Asia.

The seven islands that constitute Mumbai were earlier home to communities of Marathi language-speaking Koli people. For centuries, the seven islands of Bombay were under the control of successive indigenous rulers before being ceded to the Portuguese Empire, and subsequently to the East India Company in 1661, as part of the dowry of Catherine of Braganza in her marriage to Charles II of England. Beginning in 1782, Mumbai was reshaped by the Hornby Vellard project, which undertook reclamation of the area between the seven islands from the Arabian Sea. Along with the construction of major roads and railways, the reclamation project, completed in 1845, transformed Mumbai into a major seaport on the Arabian Sea. Mumbai in the 19th century was characterised by economic and educational development. During the early 20th century it became a strong base for the Indian independence movement. Upon India's independence in 1947 the city was incorporated into Bombay State. In 1960, following the Samyukta Maharashtra Movement, a new state of Maharashtra was created with Mumbai as the capital.

Chittagong (/ˈtʃɪtəɡɒŋ/ CHIT-ə-gong), officially Chattogram (Bengali: চট্টগ্রাম, romanized: Côṭṭôgrām, IPA: [ˈt͡ʃɔʈːoɡram] , traditionally Bengali: চাটগাঁও, romanized: Cāṭgão; Chittagonian: চিটাং/সিটাং, romanized: Sitang), is the second-largest city in Bangladesh. Home to the Port of Chittagong, it is the busiest port in Bangladesh and the Bay of Bengal. The city is also the business capital of Bangladesh. It is the administrative seat of an eponymous division and district. The city is located on the banks of the Karnaphuli River between the Chittagong Hill Tracts and the Bay of Bengal. In 2022, the Chittagong District had a population of approximately 9.2 million according to a census conducted by the government of Bangladesh. In 2022, the city area had a population of more than 5.6 million. The city is home to many large local businesses and plays an important role in the Bangladeshi economy.

One of the world's oldest ports with a functional natural harbor for centuries, Chittagong appeared on ancient Greek and Roman maps, including on Ptolemy's world map. It was located on the southern branch of the Silk Road. In the 9th century, merchants from the Abbasid Caliphate established a trading post in Chittagong. The port fell to the Muslim conquest of Bengal during the 14th century. It was the site of a royal mint under the Delhi Sultanate, Bengal Sultanate and Mughal Empire. Between the 15th and 17th centuries, Chittagong was also a centre of administrative, literary, commercial and maritime activities in Arakan, a narrow strip of land along the eastern coast of the Bay of Bengal which was under strong Bengali influence for 350 years. During the 16th century, the port became a Portuguese trading post and João de Barros described it as "the most famous and wealthy city of the Kingdom of Bengal". The Mughal Empire expelled the Portuguese and Arakanese in 1666.

The Grand Harbour (Maltese: il-Port il-Kbir; Italian: Porto Grande), also known as the Port of Valletta, is a natural harbour on the island of Malta. It has been substantially modified over the years with extensive docks (Malta Dockyard), wharves, and fortifications.

Marsamxett Harbour (Maltese pronunciation: [mɐr.sɐmˈʃɛt]), historically also referred to as Marsamuscetto, is a natural harbour on the island of Malta. It is located to the north of the larger Grand Harbour. The harbour is generally more dedicated to leisure use than the Grand Harbour.

Trincomalee Harbour is a seaport in Trincomalee Bay or Koddiyar Bay, fourth largest natural harbour in the world and situated on the northeastern coast of Sri Lanka.

Located by Trincomalee, Sri Lanka, in the heart of the Indian Ocean, its strategic importance has shaped its history. There have been many sea battles to control the harbour. The Portuguese, Dutch, French, and the British have each held it in turn. In 1942 the Imperial Japanese Navy attacked Trincomalee harbour and sank three British warships anchored there.

Mumbai (/mʊmˈbaɪ/ muum-BY; Marathi: Mumbaī, pronounced [ˈmumbəi] ), also known as Bombay (/bɒmˈbeɪ/ bom-BAY; its official name until 1995), is the capital city of the Indian state of Maharashtra. Mumbai is the financial capital and the most populous city proper of India with an estimated population of 12.5 million (1.25 crore). Mumbai is the centre of the Mumbai Metropolitan Region, which is among the most populous metropolitan areas in the world with a population of over 23 million (2.3 crore). Mumbai lies on the Konkan coast on the west coast of India and has a deep natural harbour. In 2008, Mumbai was named a alpha world city. Mumbai has the highest number of billionaires out of any city in Asia.

The seven islands that constitute Mumbai were earlier home to communities of Marathi language-speaking Koli people. For centuries, the seven islands of Bombay were under the control of successive indigenous rulers before being ceded to the Portuguese Empire, and subsequently to the East India Company in 1661, as part of the dowry of Catherine of Braganza in her marriage to Charles II of England. Beginning in 1782, Mumbai was reshaped by the Hornby Vellard project, which undertook reclamation of the area between the seven islands from the Arabian Sea. Along with the construction of major roads and railways, the reclamation project, completed in 1845, transformed Mumbai into a major seaport on the Arabian Sea. Mumbai in the 19th century was characterised by economic and educational development. During the early 20th century, it became a strong base for the Indian independence movement. Upon India's independence in 1947, the city was incorporated into Bombay State. In 1960, following the Samyukta Maharashtra Movement, a new state of Maharashtra was created with Mumbai as the capital.