Manmade mound, similar to a tell, found in late prehistoric northwest Europe, created by the continual remaking of clay floors and deposition of rubbish. Terpen were good settlement sites for the Frisians and other Germanic peoples in areas threatened by flooding. The earliest go back to the 3rd century BC and many remained in use until the Middle Ages. These nucleated settlements were indigenous to the Iron Age and Migration Period cultures of the Frisian coastlands. Excavations have shown that terps were densely populated; they contain large numbers of dwellings, including buildings in which crafts were made.