The Jätkäsaari area is comprised of four previous islands now adjoined to the continent. In addition to permanent residents, the people of Helsinki had summer villas on the islands. Boat trips were made to them, and the sand beaches attracted swimmers. The islands were occupied by industry, such as candle and tar plants, in the early 20th century. The rocks of Saukko island were quarried and their red granite can be seen on the walls of many Helsinki monuments: the Uspenski Cathedral, St. John's Church and Pitkäsilta Bridge. Construction work on the harbour began in 1913. So much seafloor was filled that the area tripled from the original plans. In 2008, the cargo ship harbour was relocated to Vuosaari, and the reconstruction of Jätkäsaari as part of Central Helsinki began. Storehouses designed by Lars Sonck, Huutokonttori that used to provide employee facilities for the port, and the massive 1970s Bunkkeri warehouse are reminders of the past.