It is located at the highest point of the city, on a rocky hill, with a panoramic view of the whole Phthiotis county. It is medieval and aged from the 5th century A.C. Inside the castle, the Archaeological Museum of Lamia is based, which is situated in an impressive building, which operated as a military camp at the time of Othon. The collections of the museum include archaeological findings from excavation research in Phthiotis and Evrytania, covering the whole prehistoric and historic period until the roman years. The findings illustrate the history of the area, which includes parts of the ancient Phthiotis, of the eastern Locris, of Dorida, Achaea and Malis (Malian Gulf area). The museum is open daily and the regular ticket costs 2 euros and the discount ticket costs 1 euro (phone number 22310 29992).