“Dharmaganja”, the nine storey temples

We find mention of “Dharmaganja” in “History of Buddhism in India” by Taranatha a 17th century Buddhist scholar and historian.
In Chapter no 20- Account of the period of the Third hostility to the doctrine and of its restoration, we find the description of the “Dharmaganja” catching fire.

“Dharmaganja” was the name of the complex which had three 9 storey temples namely, Ratnasagar, Ratnodadhi and Ratnarandaka in the sangharama of Nalaendra. In narrating the story about the fire he talks about the miraculous stream of water that came out to extinguish the fire. And towards the end there is a mention about king Buddhapaksa reconstructing it back to its original state. Description provided by Taranatha is very vague and it doesn’t mention the exact location of the “Dharmaganja” in the campus, neither is there a description of other units in the campus and their relative distances. Moreover there account of who built it and when.
In his description of causes of fire and its subsequent restoration by King Buddhapaksa he says, during one consecration organized by Kakutsiddha, a minister of King (not mentioned) two beggars were insulted by two students. This made them furious, for nine years they meditated and attained siddhi. On return they scattered charmed ashes all around and those ashes ignited the fire. Water came from 9th storey of one of the units which miraculously quelled the fire. He further adds that the fire also caused damage to the big temples and it was later reconstructed by King Buddhapaksa.
There can be two possibilities,
I. “Dharmaganja” is a part of the presently exposed structure, any of the three temples from the presently exposed one are the Ratnasagar, Ratnodadhi and Ratnarandaka
II. “Dharmaganja” being a separate unit consisting of three temples namely Ratnasagar, Ratnodadhi and Ratnarandaka
There is no other mention by any eyewitness accounts about temples with those names. There is a big contradiction between the travelogues we have been referring to so far and the accounts of Taranatha.
Other discrepancy that we find is that all the pilgrims have the associated this place and most of the structures in the temple row with Buddha while Taranatha have linked the place with Sariputra. All the temples exposed closely follow the description in the other travelogues and that leads us to believe that Dharmaganja can’t be associated with the row of temples.
There is another scenario that can be considered and that is the possibility that “Dharmaganja” was at some other place but within the boundary of the campus. For this to hold true we will have to examine the archaeological finds a bit more closely. Though it would be tough to prove or negate the existence of a Library based of Archaeological finds but so far there haven’t been a discovery about any inscriptions on any of the structure, or any donations to suggest that. The antiquities found during the excavations were not closely studied but it is pretty clear from various accounts that the building complex was not lost in the fire as there is a mention that building was restored after the fire. No remains of the massive 9 story structure have been found and the ones exposed so far don’t the description of the building or the suggested purpose.
We have at least four contemporary eyewitness accounts of travelers in different periods of time varying from 7th century to the 13th starting with Xuanzang, It-Sing, Hwui Lun to Dharmasvamin in that given order, who have left a detailed description of Nalanda Mahavihara. None of them have mentioned about a nine storey temple or any separate unit in the campus for storing the scriptures. Dharmasvamin who visited Nalanda in 13th century gives description about three types of units, the Monasteries, the row of temples and 80 other small monasteries outside the main campus.
The names of the kings referred by Taranatha as major contributors also don’t match the list of the patron to the Mahasanghrama. Another interesting piece of puzzle is the dynasty of King Buddhapaksa and his kingdom.
The only literary evidence of large scale damage to the structure was in 10th century at the time of Mahipala. Even if we consider the case where there was a huge 9 storey structure at some corner of the campus, the next valid question that arises is ‘where are the remains?’. The structure must be about 100 to 200 ft tall and it is highly unlikely that the entire structure including the foundation was selectively removed by the subsequent generations.