Sunken cities are ancient urban areas that have been submerged underwater, often due to natural disasters, rising sea levels, or human activities. These sites provide valuable insights into past civilizations, showcasing their architecture, culture, and daily life. Examples include the Lost City of Atlantis and Pavlopetri in Greece, which date back thousands of years. Archaeologists study sunken cities to learn about historical events and environmental changes. Underwater excavations reveal artifacts, structures, and even entire streets, helping researchers piece together the stories of these lost places. The preservation of these sites is crucial for understanding human history and the impact of climate change.