Bangladesh sits on the Ganges-Brahmaputra Delta, the largest river delta in the world. A delta forms where rivers slow down and drop the sand and mud they have been carrying. Over thousands of years, this process built a flat, low-lying land that is incredibly fertile. Bangladesh is roughly the size of the state of Iowa, but it has over 170 million people, making it one of the most densely populated countries on Earth. The rivers are both a blessing and a challenge. The rich soil makes Bangladesh a top rice-growing country. But during the monsoon season, which lasts from June to October, heavy rains cause rivers to overflow. About one-third of the country can flood in a bad year. Millions of people have learned to live with water. Houses are built on raised platforms. Farmers plant rice that can grow in flooded fields. Children sometimes travel to school by boat. On March 26, 1971, Bangladesh declared independence from Pakistan. The people had been treated unfairly for years. Today, Bangladeshis celebrate this day with parades and ceremonies across the country, proud of the resilient nation they have built on one of the most challenging landscapes on Earth.