The old temple to Hera was burned down in 423 B.C. and a new temple of the Doric order was built in its place, although nothing remians of the structure except for part of the stylobate.
The site was discovered in 1831 by General Gordon who dug there briefly in 1836. In 1854, limited investigations wre carried on by Rangabe and Bursian. Schlieman made soundings in 1874, although excavation on a large scale was first undertaken by the American School of Classical Studies under the direction of Charles Waldstein in 1892-1895, then again a genertion later in 1925-1928. Pre-classical remains on the acropolis and in its vicinity wre examined in excavations conducted for the American School by C.W. Blegan [AJA 1939:410-444].
Waldstein, "The Argive Heraeum," Boston, 1902, pp110-126
Caskey & Amandry, "Investigations at the Heraion of Argos," Hesp 21(1952:165-221)
Blegen, C.W., "Excavations at the Argive Heraeum," AJA 29(1925:413-428)