Why were medieval cities so tightly packed?

Medieval cities were tightly packed primarily due to the need for defense and the limited availability of space. Walls and fortifications surrounded many cities, restricting expansion and creating a compact layout. Additionally, the lack of advanced transportation and infrastructure meant that residents lived close to their workplaces, such as markets and workshops, fostering a dense urban environment. This proximity also facilitated community interactions and trade, which were vital for the city's economy.