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.