Underground bunkers are fortified structures built below ground level, designed to provide protection from various threats such as natural disasters, military attacks, or nuclear fallout. They are often constructed with thick walls and reinforced ceilings to withstand external pressures and can be equipped with essential supplies, ventilation systems, and living quarters. These bunkers can vary in size and complexity, ranging from simple shelters to elaborate facilities with advanced technology. Some are privately owned, while others are built for government or military use. The concept of underground bunkers has gained popularity in recent years due to increasing concerns about safety and security in uncertain times.