The summer theatre in the Hyvä Omatunto (Clear Conscience) ravelin

Governing Body of Suomenlinna - 1990-1993 and 2005-2007



  • 1990-1993: Helsinki open prison, Suomenlinna division
  • 2005-2007:  Helsinki open prison, Suomenlinna division for foundations, private entrepreneur (metallic structure and fabric cutting)

Annual maintenance
mounting - dismantling of fabric using a crane (cost of 10,000 € per year, one day of work)

Covered surface area: 900 m²

Number of auditorium seats: 520

Canvas: Ferrari fabrics (PVC), manufactured in Lyon

A removable covering
The ravelin dates from the 1770’s and is also casemated. From around 1830 to the beginning of the 20th century, it was used as a partially covered storeroom. From the 1960’s, successive theatre
troupes used it as a performance space.  A first cover, which the National Board of Antiquities decreed must be removable, was installed during the 1990’s. The canvas was suspended on metal cables fixed into place with hooks into the firing ranges. After 15 years of use, this cover was replaced. The new structure meets the following specifications:

  • Protection of the audience and actors from the rain and the sun. Wind and noise resistance;
  • Preservation of the site’s integrity;
  • Reasonable installation and maintenance costs.
Finance plan


  • 1990-1993 : Approximately 800,000 € (including the conversion of a wooden hangar into cloakrooms for the theatre)
  • 2005-2007 : 220 000 €
  • + 244 000 € contracting parties


Positive aspects

The cover, which looks simple in design, was very complex to fit. It was not universally appreciated. The planning permission for it was granted for a period of ten years. Although the canvas is removable, the structures which hold it up, whilst they may be dismantled, remain in place all year round. The foundations were larger than thought and vaults had to be drilled through to fix the hooks into place.

Negative aspects

Instructions for use:

  • A wind-protected installation will prevent wind passing under the canvas;
  • Water must be drained away;
  • Due to lack of water, the grass areas which are covered by the canvas turn into dry and dusty soil, which, when the wind is blowing, is unpleasant for the audience and the artists;
  • Due to lack of sunlight on the masonry and grassy banks during the month of May, the space remains quite cold;
  • The space should be ventilated during the day to avoid humidity penetrating the interior.