Shah-i-Zinda, one long walled-in street lined with mausoleums. Many of Tamerlane's relatives are buried here.

It is supposedly built around Mohammed's cousin who brought Islam to the area.  So it's considered a very holy site. A door to one of the final domed halls (called a "chortak") down the street (I ran out of batteries on my camera so I wasn't able to take a picture of it) says that three visits to this site equal one pilgrimage to Mecca.

A view down the street