The best example of these is the famous stupa at Sanchi (near Bhopal)
with massive dimensions (diameter 121.5 ft, height 77.5 ft, height of
stonerailing 11 ft). The original brick stupa built by Asoka was probably of
not more than half the present dimensions which were subsequently enlarged
by the addition of a stone-casing laced with concrete. Besides, the present
railing was a subsequent replacement for the older and smaller railing of
Asoka.
Caves
Another important heritage of the Mauryas are the caves, cut out of hard and
refractory rocks. Their interior walls are so well-polished that they shine like
mirrors. These were meant to be residences for monks (viharas) and also
served the purpose of churches and assembly halls (chaityas).
     Asoka and his grandson Dasaratha got several such cave-dwellings built
in the Barabar Hills near Bodh Gaya, and donated them to the monks of
Buddhism and the Ajivika sect. The details of two famous Barabar Caves
(Sudama and Lomas Rishi Caves) show a clear influence of wooden
architecture on rock-cut architecture.
                             BARABAR HILL
  Its four caves are the earliest examples of rock-cut architecture in India.
  Made in the Mauryan period, they became a trend in the subsequent
  centuries. Like the larger Buddhist Chaityas that were found in Ajanta and
  Karla Caves in Maharashtra, they greatly influenced the tradition of South
  Asian rock-cut architecture.
     Thus, the Barabar Caves are the earliest examples of the rock-cut method,
and mark the beginning of a great tradition which would span the next 1,000
years in the history of Indian art.