The Grand Fort
Krishna took Vishwakarma's (the architect) help to design a fort to keep
his relatives safe during Jarasandha, the king of Magadha's attacks. A
vast wall was erected within the ocean. It had well laid out roads,
gardens, and the wish-fulfilling tree kalpavriksha. Each house had
underground rooms stocked with food to survive the seige. The city was
presented with rhe celestial parijata flowers, Veruna's horse, and
Kubera's knowledge of gaining wealth.