A crannog is an ancient type of dwelling found in lakes, rivers, and marshes, primarily in Ireland and Scotland. These structures were built on stilts or platforms, often made of wood, stone, or earth, and served as homes for communities during the Iron Age and Medieval period. Crannogs were strategically located to provide protection from invaders and harsh weather. They were accessible by boat and sometimes connected to the mainland by causeways. Archaeological excavations have revealed artifacts that offer insights into the daily lives of the people who lived in these unique structures.