Gulshan e Erum was built as his personal library built by Nawab Nasir-ud-din Haider in near Qaiserbagh Lucknow. He died in the basement of this building.
It’s been under renovation now.
This thread from my recent visit
I start with vintage photos. For wh couldn’t find credit on net Suspect it’s British Library.
Lucknow historian Mr Roshan Taqui wrote many letters to the Govt emphasising it’s importance and need for preservation which led to the current restoration project.
One room on the upper floor retains some of it’s original wall paintings.
This also has trompl’oeil ( I got the correct description from Rafiq Kidwai) which is a visual illusion in art.