Archaeological Museum of Astros  was built in 1805 by Dimitrios Karytsiotis (1741-1819) as an annex of St. John’s School (1798), where young people from different villages were attending. In 1823, the famous Second National Assembly of Astros and the Kolokotronikos table took place on July 19, 1821, in honor of Dimitrios Ypsilantis. The school was destroyed in 1826 by Ibrahim Pasha, but was later restored by relatives of Karytsiotis.

In the following years, it became a school and in 1959 it became an archaeological museum. In 2008 it was closed due to earthquake damage. However, visitors can see the venue where the National Assembly took place, the courtyard with some findings from the Herod Atticus Mansion, and the two-story museum and its walls, which helped as a branch of the school.