The Largest Tsunami in History: What We Learned Since ancient times, humans have been faced with devastating natural disasters. One of the deadliest disasters is a tsunami, a huge ocean wave produced by tectonic movements, volcanic eruptions, or even falling meteorites. In history, some of the largest tsunamis have left deep imprints on society and nature. Let’s explore some of the biggest tsunamis and the valuable lessons we can learn. The 2004 Indian Ocean tsunami was one of the most famous and deadliest in history. After an earthquake measuring 9.1–9.3 on the SR near Aceh, Indonesia, this tsunami hit the coasts of countries such as Thailand, Sri Lanka and India. With estimated victims reaching more than 230,000 people, this incident teaches us the importance of an early warning system. Since then, countries along the Pacific “Ring of Fire” have begun building better monitoring systems to detect seaquakes. The 2011 Japanese tsunami, caused by a 9.0 magnitude earthquake off the east coast, added to the blacklist of tsunami events. Waves as high as 40 meters damaged much of the infrastructure, including the Fukushima nuclear reactors. The lesson here is about infrastructure resilience. Buildings and facilities must be designed to withstand these types of natural disasters to minimize damage. The tsunami in Krakatoa in 1883 is also an important record in history. This volcanic eruption caused giant waves that damaged the surrounding islands and resulted in the deaths of around 36,000 people. This event shows that volcanoes are not only dangerous because of their eruptions, but also the aftereffects they cause. The tsunami in Sanriku, Japan in 1896 also made history because it killed more than 20,000 people. This tsunami emphasized the importance of public education. Understanding tsunamis and evacuation training is crucial to saving lives when a disaster occurs. At the end of this article, it is important to emphasize that although tsunamis are a dire threat, improved technology and public awareness are essential in minimizing their impact. Research and development in the fields of geophysics and meteorology play a major role in a more effective disaster mitigation system. By applying lessons from the largest tsunami in history, we can better prepare for similar threats in the future. Disaster literacy is key in dealing with possible tsunamis, including understanding geology, developing warning systems, and continuing education among the community. As new data emerges on tsunami patterns and behavior, further research in this area will help save lives and protect critical infrastructure. The community must also be empowered to be able to face disasters, and have a clear and tested evacuation plan. In every corner of the world, the experience and knowledge of the largest tsunami in history continues to guide us in building a safer future.