Video Description: For this episode of Explore! we investigate the world of a city underground and ask the big picture question, “How can I better understand the city I live in by looking at how it operates underground?” What exists under your city that makes life in your city possible? How does your life above ground connect to an unseen infrastructure underground? Find out as you explore the underground world of a city.

• Before watching the video ask students the big picture questions: “How can I better understand the city I live in by looking at how it operates underground?” What exists under your city that makes life in your city possible? How does your life above ground connect to an unseen infrastructure underground? Allow students to share thoughts and answers or write some ideas down in a journal.
• Contact the director or an employee of your city’s sewer system. Interview him/her about your city’s system. Some questions might be: How big is it? What kind of disinfections system does it use? How is it maintained? Find out if there are places where you can go inside the sewer system and take some pictures or video to share with your classmates.
• After watching the video research the history of sewers; when they were invented and what they have been used for over the years since 2500 B.C.