The museum is housed in an imposing building, historical and architectural monument, the former Boys Gymnasium „ST. Petru and Pavel", which building began on 31 May 1865, during the ruling of Alexandru Ioan Cuza, after the designs of the known architect Alexandru Orascu.

The permanent exhibition of the museum was opened on the 1st of September 1975 and had representative pieces for the national history, authentic proofs of the people life on Prahova region along the centuries.

The building was very damaged by the 1977th earthquake and by those from the 80’s, so the museum was closed in 1990. Till 1995 the building was in reconstruction. After the restoration, keeping the initial aspect till the last detail, a new permanent exhibition was organized, on modern criteria, putting in evidence the local specificity in the national context.

The History and Archeology County Museum, present to the visitors proofs of the civilization evolution in Prahova region through its 150.000 pieces from its patrimony.

In 1966, November 30, the first halls of the permanent exhibition were opened: the coins collection, the medals collection, the room dedicated to the writer I.A. Bassarabescu and the Lapidarium.