In 1992, a Dutch doctor named Josh von Soer Clemm von Hohenberg wrote a letter to Henning Voscherau, the mayor of Hamburg, Germany, requesting that a street be named after Marie Nyswander.

The doctor had never met Marie, but he had founded a clinic for treating people with drug addiction, and he’d seen methadone treatment — co-developed by Marie — save lives. Four years later, doctors gathered on a street in northwest Hamburg to celebrate that street’s new name: Nyswanderweg. We’re investigating how German streets get their names, and why so few of them honor women like Marie, who have made historic achievements.