Ask an adult what they remember about being three years old, and it’s likely they won’t recall much. That disconnect can be a problem for advocates of child-friendly cities. If people can’t relate to three-year-olds, they’re less likely to support projects that benefit small children and their caregivers. That’s why Rodrigo Ramalho, head of the Department of Education and Physical Activity in Torres Vedras, Portugal, uses periscopes. Made of cardboard and mirrors, these simple devices allow adults to view their surroundings from the height of 95 centimetres, the average height of a three-year-old. “Parking meters are huge at 95 centimetres,” recalls Filipa Baptista, a founding member of the Portugal branch of the International Play Association (IPA). A giant stuffed bear in a storefront was “terrifying.” Both Ramalho and Baptista say this literal shift in perspective can be transformative. “If everyone could have that experience,” says Baptista, “our work would be so much easier.”