Before leaving the neighbourhood of Persepolis, Niebuhr visited Istakhr and Naksh-i-Rustam, but he did not go on to Murgab. At Istakhr he saw two columns still standing, and he noted the massive blocks of the gateway.[95] He made no attempt to enter any of the tombs, which he says could not be done ‘without the risk of losing one’s life.’ That risk, such as it was, was, however, undertaken in the following year by Mr. Hercules, who had provided himself with tools in the case of necessity; but he found that some earlier visitor had pierced a hole through the top, and that there was nothing but dust remaining. Niebuhr has not noticed the inscription on the Tomb of Darius; but his accurate copies of the Pehlevi made at this spot and at Naksh-i-Rejeb opposite were the first that enabled Silvestre de Sacy to translate that language. We shall see in a future chapter that before the close of the century the writings of Le Bruyn and Niebuhr had attracted a fair share of attention among European scholars; and the copies they had made of the inscriptions became the object of sedulous study, especially in the North. In Göttingen, the interest excited by the description of the ruins of Persepolis gave rise to an extremely heated controversy between Heeren and Herder. The former, in an early edition of the ‘Historical Researches,’ maintained that they were of Achaemenian origin. Persepolis, he says, ‘as the residence and place of sepulture of the Persian kings, was considered in the light of a sanctuary, and held to be the chief place in the kingdom.’ Herder, on the other hand, contended for its Jamshid origin, and supported his opinion in a series of very acrid ‘Persepolitan Letters.’[96] The question was of more importance than might at first sight appear, for upon its decision depended the royal names that should be looked for in the inscriptions. George Grotefend, a student in the University, who made the first successful attempt to decipher them in 1802, adopted the opinion of Heeren, and his investigations were largely based upon the conviction that the names of Darius and Xerxes could not fail to be found hidden in the cuneiform characters.