Crannogs are anchored islands, basically the same as breakwaters or polders. Put down some rocks or junk cars in a lake, and pretty soon plants will turn the deposit into an island.
Quages are floating islands, usually formed by nature. A cluster of logs floats around in a lake and gradually accumulates plants and soil, without ever touching bottom.
The truly dramatic aspect of crannogs is the TIME SPAN:
Hundreds of crannogs were created in Scotland, Wales and Ireland, between 4,000 B.C. and the 16th century A.D., by building up a shallow reef or an elevated portion of a lakebed with any available natural material — such as stone, timber or peat — to a diameter of nearly 100 feet (30 meters). A lot of trade and communication occurred along the lakes and estuaries where crannogs were built. Used as farmsteads during the Iron Age (eighth century B.C. to the first century A.D.), crannogs evolved into elite gathering places in the medieval period (fifth to the 16th centuries A.D.), according to evidence of feasting and plentiful artifacts, such as pottery, uncovered there.
Brown and colleagues investigated one site in Scotland (500 B.C. to A.D. 10) and two in Ireland (A.D. 650 to 1300) to better understand the purpose of these crannogs.
Crannogs were built and used for 5500 YEARS.
Some were used as farms for 900 YEARS.
Some were used as party palaces for 1100 YEARS.
Those numbers are unimaginable in this part of the world, even when we include the old original tribes. Everyone on this continent was moving around, conquering new territory, genociding the previous tribe. No single structure was used for 5000 years.
Ran into a pretty good summation yesterday:
100 miles is a long distance in Europe. 100 years is a long time in America.