Dayahatyn (also spelled Dayakhatyn or Daya-khatyn or Bai Khatyn in folk) is a medieval caravanserai, sitting on the left bank of the Amu Darya.

It is around 170 km to the northwest of the modern city of Turkmenabat, Lebap welaýaty, near the border between Turkmenistan and Uzbekistan.

In the 11th century, it was transformed into a caravanserai with fascinating brick-structures, providing shelter for not only caravans but also elites during their long journeys.

One is that the Rabat of Dayahatyn was built by a local ruler, who wished to hide from a beauty named Daya.

Another version is about a rich man named Bay, who suspected his wife in infidelity and left home in the cloth of poor dervish.