[4] It is said that after Nawazish died, Ghaseti Begum lived here until Nawab Siraj ud-Daulah took over the palace and seized the residents' in 1756 AD.

With this money he built a similar lake with a beautiful palace, Hirajheel, on the opposite side of the Hooghly River.

The palace has a lofty gateway, a mosque known as the "Shahamat Jang" and the Kala Masjid and some other buildings which were all built by Nawazish.

As far as etymology is concerned, the palace has been named so as it was built using black basalt pillars which were brought from the ruins of Gaur.

The mosque rests on several octagonal drums which are plain and are devoid of any decoration and the domes are crowned by lotus and kalasha (pot) finials.

It also has four octagonal minarets at the four corners which taper upwards and are topped by bulbous kiosks which are supported on slender pillars.

To the west of the mosque and beyond the compound wall of the Motijhil Lake, stands a ruined royal gateway, also built by Nawazish Muhammad Khan.

The slab embedded on the grave says that his son was born on 20 December 1779 and died on 3 March 1785 (aged 5 years, 2 months and 11 days).