The Rotes Turm — Red Tower — is the most visible remnant of Winterthur's medieval fortifications, standing at the northern edge of the old town where the main pedestrian shopping street begins. The round tower, built around 1264, served as the city gate and later as a prison. It was restored in the 20th century and now stands somewhat unexpectedly in the middle of the commercial street, dwarfed by department store facades but still commanding in its own way.
The tower is not open to the public inside but is worth a pause as a landmark that helps you read the old street plan: the main artery of the old town follows the course of the medieval market street, and the Rotes Turm marked one of its ends. The other tower from the same fortification system, the Oberer Turm, stands at the southern end of the same street and can be seen from here.