The Canal of Corinth separates mainland Greece from the Peloponnese Peninsula. Among others, Rome's infamous emperor Nero unsuccessfully attempted the construction of such a canal, but it wasn't until the late 19th century that this task was completed. The almost vertical, up to 63 m (207 ft.) high flanking cliffs of the 6,343 m (20,810 ft.) long canal provide a unique cross-section of the local geology. The cementation of individual particles with carbonates lends a relatively high stability to the marine and lacustrine sediments constituting the canal walls. Nevertheless, faulting of the sediments and seismicity in this tectonically active region make the rocks prone to landslides, some of which have required the canal to be temporarily closed.

The picture in the inset was taken during a flight from Athens to Munich and shows the canal in its complete length, connecting the Gulf of Corinth (upper left) with the Aegean Sea (lower right).

Stolen from the Earth Science Pic of The Day archives