The fortress, built by King Herod on Mount Masada, is well preserved for its two thousand years of age. What I have not seen in other fortresses is the dovecote, where birds were bred to feed the defenders of the besieged fortress. You can climb the mountain by funicular or walk for 40 minutes along the "snake road".
Quote from the UNESCO website: "Masada is a natural rocky fortress in the Judean Desert, majestically beautiful and dominating the Dead Sea lowland. It is a symbol of the ancient Israelite kingdom, its brutal destruction and the last resistance that Jewish patriots put up against the ancient Roman army in 73 AD. It was built as a palace complex in the classical style of the early Roman Empire by Herod the Great, king of Judea (reigned 37-4 BC) The camp, fortifications and assault ramp, located in the surroundings of Masada, are most well recognized surviving traces of ancient Roman siege structures.