The oldest standing structure in Ethiopia, the Temple of Yeha, is located in Yeha. This is a tower built in the Sabaean style, and dated through comparison with ancient structures in South Arabia to around 700 BC. Although no radiocarbon dating testing has been performed on samples from site, this date for the Great Tower is supported by local inscriptions.[2] David Phillipson attributes its "excellent preservation" to two factors, "the care with which its original builders ensured a level foundation, firmly placed on the uneven bedrock; and to its rededication -- perhaps as early as the sixth century AD -- for use as a Christian church."[2] Two other archaeological sites at Yeha include Grat Beal Gebri, a ruined complex distinguished by a portico 10 meters wide and two sets of square pillars, and a graveyard containing several rock-hewn shaft tombs first investigated in the early 1960s.