Why were the cities of nanjing calicut mogadishu and Venice significant?

Nanjing, Calicut, Mogadishu, and Venice were significant as major trading hubs in their respective regions. Nanjing was a key center in China for commerce and culture, particularly during the Ming dynasty. Calicut was pivotal for spice trade in India, attracting merchants from across the world. Mogadishu served as an important port city in East Africa, facilitating trade between Africa, the Middle East, and Asia, while Venice emerged as a vital maritime power in Europe, connecting trade routes between the East and West.