Mausoleum of Satrap Hekatomnos, pointed as the discovery of the century in the archaeological world, was built at a position dominating the ancient Mylasa city and can be seen from any point of the settlement. The construction of this magnificent mausoleum must have been started within the first quarter of 4th century BC. The structure was constructed by Maussollos, son of Satrap Hekatomnos whose name was given to the dynasty, upon the latter's sudden death, but the construction was left unfinished following the decision of Maussollos about moving the capital from Mylasa to Halicarnassus. The Mausoleum is the predecessor of Halicarnassus Maussolleion, accepted as one of the seven wonders of the ancient world, and is included in Temporary World Heritage List of UNESCO. The reason of establishing the tomb structure here is to build a magnificent mausoleum competing with the temples of Antiquity by resting the burial chamber in bedrock. Entrance to the burial chamber is provided through a corridor (dromos) of 8.09 meter long. A marble sarcophagus surrounded by reliefs at four faces is present in the burial chamber resting on the bedrock made by vaulted overlaying technique and colored murals take place on the internal walls of the chamber. The sarcophagus in the burial chamber is 2,90 x 2,28 m in size and 1,54 m high. lt has a lid having a pediment whose top and corners are ornamented by statuettes. The elder son of Maussollos, who came to the throne after Hekatomnos' death, had it manufactured. Four faces of the sarcophagus were furnished by high-quality reliefs which may compete with the most famous artefacts of the Classical Age.The reliefs on the front face is a "Feast Scene" where Hekatomnos, reposing on a couch, is depicted in the middle of the scene with his wife Aba beside him and his children Maussollos and Artemisia in front. The figures standing to the left and right of the family are the palace staff and pages. At the back side of the sarcophagus, in the middle of "Lion Hunt" scene, the moment when Maussollos rides a horse provides the last blow to his hunt by the javelin (lost today) he holds at his raised hand. Hunt servants, dressed as Persians, with their dogs stand behind and his hunt companions in front of Maussollos.