New Delhi, May 4 -- I take a beat before entering Kalutara Stupa, one of the most sacred sites on Sri Lanka's Buddhist trail. That's when I spot the elaborately carved semi-circular stone slab at the entrance. The sculptural design comprises a half lotus at the centre, surrounded by concentric bands showcasing a procession of animals, a foliated pattern and geese.

The local accompanying me to the temple tells me that the sandakada pahana, commonly known as moonstone (not to be confused with the gem mined nearby), is a unique feature of Sri Lankan culture and Buddhist architecture. "It first made an appearance in the later stage of the Anuradhapura period (377 BCE-1017 CE), synonymous with the Golden Age of Sri Lanka, and was typically po...