Corinth Canal in Greece is a very popular architectural attraction. It connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. This canal is carved down into the rock. It is around 4 miles long and is only 70 feet wide at the base.
The Castle of Methoni in Messenia, Peloponnese, Greece: The port was on the route between Venice and Eastern markets, and the Holy Land. Beginning in the Venetians took the area from pirates and fortified it. 300 years later, it fell to the Ottomans.