The Georgetown Steam Plant is a National Historic Landmark and is also a designated National Historic Mechanical Engineering Landmark. It is important because it is one of the first electrical plants in Seattle, and the inexpensive electricity it produced helped to greatly fuel Seattle's development. The building is open to the public the second Saturday of every month from 10:00am to 2:00pm, with free guided tours at 11:00am and 1:00pm. Admission is free and no reservations are required. Because it is a formal industrial site, please visit the city's web site to learn about the correct gear to wear.