The temples on the Acropolis are currently undergoing restoration
A ruined theatre under the Acropolis, believed to be the birthplace of modern theatre, is to be partially restored.
The restoration of the Theatre of Dionysos will include extending and modernising surviving stone seats, but no new performances are planned there.
Works by playwrights such as Euripides and Sophocles premiered at the open air theatre more than 2,500 years ago.
"It is here that the masterpieces of ancient drama were first performed," said architect Constantinos Boletis.
The 6m euro (£5.4m) project is expected to be completed by 2015.
Theatre first emerged as an artform in Athens in 6th Century BC, at a competition for playwrights held during the annual festival of Dionysos.
Standing on the southern slopes of the Acropolis Hill, the theatre is "of immense historic significance," said Mr Boletis.
Originally a terrace where spectators sat on the ground above the circular stage, the theatre was rebuilt in limestone and marble during the 4th Century BC and could seat up to 15,000 spectators.
A small section of the seating area will be rebuilt using a combination of original stone and modern materials.
"The programme will have a major impact on the overall aspect of the monument," said Mr Boletis, but added that plans to host new musical and theatrical performances at the venue were "abandoned in the mid 1970s".