I visited the silk road site of Anau in June 2017. Being relatively close to Ashgabat (around 8km) I made an extra effort to visit the remains of the Seyitdzhemaliddin Mosque included on Turkmenistan's tentative list.
Anau derives from Abi-anau meaning new water and surely enough there's a well and water system just next to the mosque. The mosque was heavily damaged by the Ashgabat earthquake, however locals still pray (mostly for fertility) at this site. There are a few turquoise tiles left but nothing really outstanding which would add value to the WH list in my opinion.