Many large, impressive things have been created in Minecraft, from scale models of the USS Enterprise to entire U.S. cities. Yet nothing is quite like this, Atropos — a Steampunk-themed city placed on the back of an enormous turtle.
Atropos is the work of user CARLOOO and required five months to complete. Previous iterations of the city included one placed on the back of a whale.
Atropos may be downloaded here.