Explanation: The definition of a harbor includes both natural indentations and those that are artificially constructed or modified by human intervention.

Explanation: While often used interchangeably, a port is a specific man-made facility within a larger harbor area, designed for loading, unloading, and passenger embarkation/disembarkation.

Explanation: The fundamental characteristic defining a harbor is its provision of a sheltered body of water, whether natural or artificial, that allows for the safe mooring of watercraft.

Explanation: A port is defined as a man-made facility within a harbor, specifically designed for the functional aspects of loading, unloading, and passenger transfer, whereas a harbor refers to the broader sheltered body of water.

Explanation: Artificial harbors are indeed created or altered by human activity, and those formed by dredging necessitate continuous maintenance to ensure adequate depth.

Explanation: Prior to its initial dredging in the early 20th century, Long Beach Harbor consisted of shallow salt marshes and tidal flats, rendering it unsuitable for modern merchant vessels.

Explanation: The Ancient Egyptian site at Wadi al-Jarf on the Red Sea coast is recognized as the oldest artificial harbor, dating to the reign of King Khufu.

Explanation: Cothons were fortified, artificial harbors built by the Ancient Carthaginians, not natural harbors used by the Ancient Greeks.

Explanation: The Jebel Ali harbor is recognized as the world's largest artificially created or man-made harbor, not a natural one.

Explanation: The construction methods for artificial harbors include building breakwaters, sea walls, jetties, and dredging. Utilizing natural geological fault lines is not mentioned as a method.

Explanation: Before its transformation through dredging, Long Beach Harbor was characterized by shallow salt marshes and tidal flats, making it unsuitable for modern merchant shipping.

Explanation: The Ancient Carthaginians are credited with constructing 'cothons,' which were fortified artificial harbors serving both military and commercial functions.

Explanation: A significant number of natural harbors are indeed geologically identified as rias, which are characteristic submerged river valleys.

Explanation: Natural harbors have historically held significant strategic and economic importance precisely because their inherent protection minimizes or negates the necessity for artificial breakwaters.

Explanation: Many natural harbors are geologically categorized as rias, which are distinctive submerged river valleys formed by rising sea levels.

Explanation: Natural harbors have been strategically and economically vital due to their inherent protection, which minimizes or removes the necessity for artificial breakwaters, thereby ensuring calmer and safer waters for maritime activities.

Explanation: Conversely, an ice-free condition is a significant advantage for polar harbors, enabling continuous maritime access and operations that would otherwise be impeded by ice.

Explanation: Winter Quarters Bay, the world's southernmost harbor, experiences variable ice-free conditions, which are dependent on the prevailing pack ice during the summer months.

Explanation: According to 2017 data, the Port of Ningbo-Zhoushan held the distinction of being the world's busiest harbor based on cargo tonnage.

Explanation: Tanjung Perak is explicitly identified as a famous example of a natural harbor in Indonesia, not an artificial one.

Explanation: The harbor of Gorey, Jersey, is noted for the characteristic that it 'falls dry at low tide,' meaning it is not fully submerged.

Explanation: Punta del Este's harbor has indeed earned the moniker 'Monte Carlo of South America,' reflecting its status as a renowned and glamorous destination.

Explanation: The Port of Szczecin is a significant port facility located in Poland, not Germany.

Explanation: Valparaíso, Chile, is a major port city situated on the Pacific coast of South America, not the Atlantic coast.

Explanation: The Grand Harbour and Marsamxett Harbour are both explicitly identified as natural harbors within Malta.

Explanation: Pearl Harbor in Hawaii is specifically listed as a natural harbor in the United States, not an artificial one.

Explanation: Both Milford Haven and Poole Harbour are indeed recognized as natural harbors located within the United Kingdom.

Explanation: Kaliningrad, Vladivostok, and Saint Petersburg are all listed among the natural harbors found in Russia.

Explanation: Manukau Harbour and Wellington Harbour are both natural harbors located in New Zealand, not Australia.

Explanation: Kyiv, Odesa, and Zaporizhzhia are indeed listed among the natural harbors found in Ukraine.

Explanation: Busan, Gwangyang, and Ulsan are all recognized as natural harbors located in South Korea.

Explanation: Port Phillip in Melbourne, Victoria, is indeed listed as a natural harbor within Australia.

Explanation: Cartagena, Colombia, and San Antonio, Chile, are examples of natural harbors located in South America, not North America.

Explanation: Both the Port of Casablanca in Morocco and Durban in South Africa are cited as examples of natural harbors on the African continent.

Explanation: Haifa Bay is a natural harbor located in Haifa, Israel, within the Middle East, not in Japan.

Explanation: Kobe Harbour and Tokyo Bay are both explicitly mentioned as natural harbors located in Japan.

Explanation: The Old Harbor in Lüneburg, Germany, is depicted as a historical harbor setting, not a modern, industrial port.

Explanation: Hammerfest, Murmansk, and Valdez are cited as examples of ice-free harbors. Long Beach, United States, is not mentioned in this context.

Explanation: Winter Quarters Bay in Antarctica is identified as the world's southernmost harbor, with its ice-free status varying based on the prevailing pack ice conditions during the summer.

Explanation: Based on 2017 data, the Port of Ningbo-Zhoushan was recognized as the world's busiest harbor in terms of cargo tonnage.

Explanation: The aerial view of New York Harbor referenced in the source material prominently displays the Hudson River and the East River.

Explanation: Tanjung Perak is highlighted as a famous natural harbor located in Indonesia.

Explanation: The source material indicates that Port Jackson is another formal name for Sydney Harbour.

Explanation: A notable characteristic of the harbor of Gorey, Jersey, is that it 'falls dry at low tide,' meaning the water recedes significantly.

Explanation: Punta del Este's harbor has been colloquially referred to as the 'Monte Carlo of South America,' reflecting its reputation.

Explanation: Halifax Harbour in Nova Scotia is explicitly listed as a natural harbor located in Canada.

Explanation: Mumbai, Chennai, and Cochin Port are listed as natural harbors in India. Koyilandy Harbour is not included in this list.

Explanation: The Grand Harbour and Marsamxett Harbour are specifically identified as natural harbors located in Malta.

Explanation: San Francisco Bay is listed as one of the natural harbors located within the United States.

Explanation: Poole Harbour is identified as a natural harbor located in England, United Kingdom.

Explanation: Kaliningrad, Vladivostok, and Rostov-on-Don are listed as natural harbors in Russia. Pechenga is mentioned as an ice-free harbor but not explicitly categorized as a natural harbor in the provided list for Russia.

Explanation: Manukau Harbour is explicitly listed as a natural harbor located in New Zealand.

Explanation: Odesa is listed among the natural harbors found in Ukraine.

Explanation: Mahón harbour in Menorca is listed as a natural harbor located in Spain.

Explanation: Gwangyang is listed among the natural harbors found in South Korea.

Explanation: Port Stephens is listed as a natural harbor located in Australia.

Explanation: Rio de Janeiro (Guanabara Bay) is listed as a natural harbor located in South America.

Explanation: Maputo, Mozambique, is listed as a natural harbor located in Africa.

Explanation: Haifa Bay in Haifa, Israel, is listed as a natural harbor located in the Middle East.