Underground tours are guided excursions that explore subterranean spaces, such as caves, tunnels, or historical sites. These tours often provide insights into the geology, history, and cultural significance of the underground environment. Participants can learn about the formation of caves, the use of tunnels in urban development, or the stories of people who lived and worked in these hidden areas. Many cities offer underground tours that highlight their unique histories, such as the Catacombs of Paris or the Seattle Underground. These experiences can be both educational and adventurous, allowing visitors to discover a different perspective of the city or natural landscape above.