Since Naser Khosrow has mentioned Bagh-e-Eram in his poetry it means that it was not ilkhanate who made it. rather it goes back to samanide era: Abu Mo’in Hamid ad-Din Nasir ibn Khusraw al-Qubadiani or Nāsir Khusraw Qubādiyānī [also spelled as Nasir Khusrow and Naser Khosrow] (1004 – 1088 CE) (Persian: ناصر خسرو قبادیانی) was a Persian poet, philosopher, Isma'ili scholar, traveler and one of the greatest writers in Persian literature. Both the building and the garden were built during the middle of thirteenth century by the Ilkhanate or a paramount chief of the Qashqai tribes of Pars. The original layout of the garden however, with its quadripartite Persian Paradise garden structure was most likely laid in thirteenth century by the Seljuqs, and was then referred to as the "Bāq e Shāh" ("the king's garden" in Persian) and was much less complicated or ornamental.Cornelius de Bruyn, a traveller from the Netherlands, wrote a description of the gardens in the eighteenth century.
Over its 150 years the structure has been modified, restored or stylistically changed by various participants. The building faces south along the long axis. It was designed by a local architect, Haji Mohammad Hasan. The structure housed 32 rooms on two stories, decorated by tiles with poems from the poet Hafez written on them. The structure underwent renovation during the Zand and Qajar dynasties.
Today, Eram Garden and building are within Shiraz Botanical Garden (established 1983) of Shiraz University. They are open to the public as a historic landscape garden. They are World Heritage Site, and protected by Iran's Cultural Heritage Organization which like many other monuments they do not care about. Visiting the 540 years old building should be banned and all heavy traffic nearby too.