Eureka is a fitting name for Airship Venture's 246-foot-long zeppelin, an astounding aeronautical innovation. Longer than a Boeing 747, the gentle behemoth takes to the skies after filling its hull with nonflammable helium gas. The great ship is run by husband-and-wife team Brian and Alex Hall, who channeled their entrepreneurial spirit and love of aeronautics into the US's first and only zeppelin. The airship soars over San Francisco regularly on tours of the city and surrounding area, and can even do long-distance flights to Los Angeles, the Sonoma Valley, or Never Never Land. Intrigued passengers can also take the ground tour to see the zeppelin and its inner workings up close.