Ancient Records of the Stupa

This presently existing 2nd Century B.C. work of architecture has been recorded copiously in writing several centuries ago. The building of these structures have been recorded in several writings - The Mahavamsa (or Great Chronicle of Ceylon), the Thupavamsa, and others. The Mahavamsa was written around the 5th - 6t h centuries A.D. based on even earlier records such as the Dipavamsa and other records. The commentaries on the Mahavamsa, the Wansatthappakasini (Mahawansa Tika) are a useful elucidation. The texts have been commented and translated by many writers and the work (as available today) is enriched with many footnotes and references. 
The Mahathupa was found in a seemingly collapsed state and clothed in vegetation, when a Major Skinner made his way to Anuradhapura which lay seemingly .deserted for hundreds of years after its decline from the Golden Age.
J.G. Smither, in his work the Architectural Remains of Anuradhapura, Ceylon meticulously notes the architectural findings along with measured drawings, recording the physical existence of the Stupas. But of the interior of the Mahathupa there is no archaeological excavation work to date and we are left to faith and conjecture.