What is "shadiyakh"

Shadiyakh or Shadyakh (in Persian: شادیاخ, presumably, a contracted form of شادی کاخ, Shadi-Kakh means (The) Palace of Happiness) was one of the main Palaces, Gardens and Great Neighborhoods of old Nishapur that was established by Abdullah ibn Tahir al-Khurasani in the 9th century AD, becoming more important and populated after that. Some notable people like Attar lived there. Attar's tomb is now in that area. This palace was perhaps completely ruined in 13th century AD.

Now Shadyakh Is a national Iranian monument, with a registration number of 10910.