There used to be two huge stupas at Sarnath, one marking the place where the Buddha proclaimed the Dhamma to the world for the first time and the other, well, we’re not sure what it was meant to mark or commemorate. When the Chinese pilgrim Huien Tsiang was saw it in the 7th century he was told it was built to commemorate an event in one of the Buddha’s last life. I suspect it originally commemorated the second discourse the Buddha delivered at Sarnath, the Anattalakkhana Sutta. The first of these stupas was demolished in 1795 to provide building material for a market. The second we was in the process of being demolished when work was halted for some reason, allowing us today to get some idea what a partially complete Gupta period stupa looked like. This stupa is now called the Dharmek Stupa and is the structure most often associated with Sarnath. Here are three images of it – the first from 1823, the second from the late 19th century and a modern photo of it.