The circle-shaped building Circle House [Ympyrätalo], is a landmark in the streetscape of Hakaniemi and Eläintarhanlahti bay in Kallio district. The monumental office building’s ground floor has business premises. The ribbon windows and copper cladding form a distinctive look to the building. At the time of its construction, the building represented a new kind of big-city architecture in the streetscape of the Hakaniemi area. The building’s monumentalism is especially impressive with the illumination at nighttime.

Circle House was planned by Kaija and Heikki Siren Architects, one of the most well known architectural practices of the time. The building was planned to form a pair with the neighbouring Kallio Municipal Offices, also designed by Kaija and Heikki Siren Architects, and completed in 1965. Both buildings were historically large developments in central Helsinki in the 1960s. Circle House was completed in 1968.

The refurbishment of the building was made in the early 2000s. The refurbishment was designed by Siren Architects, run by Kaija and Heikki Siren’s son, architect Jukka Siren. One of the office room’s interior was maintained in its original shape.