Archaeological exploration of ancient Tiryns, which still continues, shows that the area of the acropolis was occupied in Neolithic times, about 7,000 years ago. The citadel makes use of a long, low outcrop, on which was set the circuit wall of gigantic limestone blocks of the type called "cyclopean" because the ancients thought they could have been handled only by the giant cyclopes—the largest block is estimated at more than 15 tons. Via the cyclopean ramp the citadel was entered on the east side, through a gate leading to a narrow passage between the outer and inner walls. You could then turn right, toward the residential section in the lower citadel, or to the left toward the upper citadel and palace. The heavy main gate and second gate blocked the passage to the palace and trapped attackers caught between the walls. After the second gate, the passage opens onto a rectangular courtyard, whose massive left-hand wall is pierced by
a gallery of small vaulted chambers, or casemates, opening off a long, narrow corridor roofed by a corbeled arch. (The chambers were possibly once used to stable horses, and the walls have been worn smooth by the countless generations of sheep and goats that have sheltered there.)
An elaborate entranceway leads west from the court to the upper citadel and palace, at the highest point of the acropolis. The complex included a colonnaded court; the great megaron (main hall) opened onto it and held the royal throne. Surviving fragments suggest that the floors and the walls were decorated, the walls with frescoes (now in the National Archaeological Museum in Athens) depicting a boar hunt and women riding in chariots. Beyond the megaron, a large court overlooks the houses in the lower citadel; from here, a long stairway descends to a small postern gate in the west wall. At the excavated part of the lower acropolis a significant discovery was made: two parallel tunnels, roofed in the same way as the galleries on the east and south sides, start within the acropolis and extend under the walls, leading to subterranean cisterns that ensured a continuous water supply.
From the palace you can see how Tiryns dominated the flat, fertile land at the head of the gulf of Argos. Pioneering German archaeologist Heinrich Schliemann (1822–90), in his memoirs, waxed rhapsodic when recalling this scene: "The panorama which stretches on all sides from the top of the citadel of Tiryns is peculiarly splendid. As I gaze northward, southward, eastward, or westward, I ask myself involuntarily whether I have elsewhere seen aught so beautiful..." The view would have been different when Tiryns thrived around 1400 BC: the ancient shoreline was nearer to the citadel, and outside the walls there was an extensive settlement. Profitis Ilias, the prominent hill to the east, was the site of the Tiryns cemetery.