Underwater ruins are remnants of ancient structures that have been submerged beneath bodies of water, often due to rising sea levels, natural disasters, or human activities. These sites can include sunken cities, temples, and shipwrecks, providing valuable insights into past civilizations and their cultures. Explorations of underwater ruins are conducted using specialized equipment like submersibles and remotely operated vehicles (ROVs). Notable examples include the ruins of Atlantis, the Bimini Road, and the ancient city of Heracleion in Egypt. These discoveries help archaeologists understand historical architecture and maritime trade routes.