Before leaving Samos we enjoyed breakfast overlooking the Aegean Sea and took a walk downtown. We checked out of our hotel and said goodbye to our new friends there before visiting the Eupalinos Tunnel. It is an underground water/aquaduct system that was built into a mountain by two crews, each working from opposite ends and meeting in the middle. It was a good thing that they gave us hard hats because the ceiling was low and the floor of the tunnel was slippery in some spots. It was such a unique experience. It was built in 550 BC and is over 1000 meters long. The importance of precision in their mathematic calculations and geometric measurements was evident when we got to the middle where the two crews met to connect the tunnel. We then hiked over to the Monastery of Panagia Spiliani that was also built into the mountain. We got to enter a cave in the back that was actually used as a church. The cave was large and had furniture, religious portraits, and candles lit by visitors. From the front of the monastary you could look down and see a fantastic view of the town of Pythagorio, including a castle, port, and the Samos airport, which was where we headed next to move on to our second destination. It took less than an hour to fly back to Athens which is where we were happily (and finally) reunited with our luggage after 3+ days. Fortunately we were prepared by packing a few days worth of outfits and some toiletry items in our carry-ons just in case. While Athens and Samos are different in many ways, there is one thing they have in common: philoxenia. It is a Greek term meaning "friend of the stranger" and is basically a way of life for Greek people. Everyone is extremely friendly and will go out of their way to welcome you to their country and provide hospitality. After checking into our hotel we realized the hotel's logo was a pi symbol (perfect for two math teachers!). The modern room has a huge balcony with a view of the Acropolis in the distance.