EUROPEAN NIGHT OF MUSEUMS: On Saturday 19 May 2012 the Acropolis Museum celebrates the European Night of Museums and will be open from 8 a.m. until 12 midnight (free entry from 8 p.m. onwards). At 9:30 p.m. in the Museum’s entrance courtyard, the Athens Municipality Symphonic Orchestra will present the latest symphonies by W. A. Mozart and F. J. Haydn, two of the most important representatives of the Classical era.