History
Humayun built several structures in close proximity to the Dargah of Hazrat Nizamuddin. Two of them were Nila Gumbad and Sabz Burj, both of which are irregular octagons in plan.
Architecture
The central chamber of Sabz Burj is connected through four axial passages to the lofty pishtaqs on the main outer faces, which alternate with smaller half-octagonal arched niches on the narrower faces. As with Humayun’s Tomb, Sabz Burj has a double dome, with the outer dome and tall drum covered with tiles.
Conservation
The dome was re-clad with tiles in the 1980s, and since then, Sabz Burj suffered from water seepage, loss of incised plaster patterns and tiles from the drum, as well as severe structural deterioration.