text: An early example of this system, which connected San Pablo Bay with its namesake California city, was the Sonoma Prismoidial.
full_question: An early example of this system, which connected San Pablo Bay with its namesake California city, was the Sonoma Prismoidial. Louis Brennan patented a system of this type for military use which employed a pair of gyroscopes. A suspended version of this technology designed by Eugen Langen in Wuppertal is the oldest of them still in use today. In 2013, one of these systems circling Darling Harbour in downtown Sydney was shut down, and it has been criticized for the difficulty of providing branching service. American examples of this technology include a Seattle system that opened for the 1962 World's Fair and one connecting the casinos of the Las Vegas Strip. For 10 points, name this ever-futuristic type of train that runs on a single beam.
first_sentence: An early example of this system, which connected San Pablo Bay with its namesake California city, was the Sonoma Prismoidial.
raw_answer: monorails [prompt on train systems until "train" is read]