The Seattle Underground Tour is a guided walking tour that explores the hidden underground passageways of Seattle, Washington. These tunnels were once the main street level in the late 19th century but were buried after the Great Seattle Fire of 1889. The tour provides insights into the city's history, architecture, and the challenges of urban development. During the tour, visitors can see remnants of old storefronts and learn about the lives of early Seattle residents. The experience combines storytelling with historical facts, making it an engaging way to discover the city's unique past while walking through its underground spaces.