The industrial buildings were mostly placed on the Hietalahdenranta side of the lot, and the rest of the area was made into a park.
Even though the park was privately owned, it was opened to the public in 1835 and soon became a popular vacation resort for Helsinkians.
The tunnel with a concrete roof was built already in 1967, as well as a number of additional buildings for the Sinebrychoff factory and a new residential block to the south of them a few years later, separated from the industrial areas by the Mallaskatu street.
Shrinking the park area and the planned office skyscraper caused huge opposition.
The park area had already been transferred into the ownership of the city, and there were extensive renovation and repair work there in the 1980s.