Pengerkatu, which runs along Hämeentie, is a modest but special destination in Helsinki - Torkkelinmäki. As the name implies, the street is paved with stone walls on three different levels. The wall structures were built in the 1920s, and is a masterpiece of its era, Kallio's own rock was utilized in the construction.
The technology related to quarrying and stone processing was not as advanced as it is today, most likely the unemployed were utilized in the jobs. The walls of the area are really skilfully piled using natural stone, specializing in the cityscape of the area.