Mystery object discovered at Kruunusilto bridge construction site in Helsinki

A concrete structure of unknown origin has been discovered at the construction site for the Kruunusilto bridges in Helsinki’s Hakaniemi district. The communications team for the project shared an image of what they have humorously dubbed a “mystery object” on social media, inviting the public to help identify it. The post playfully suggested possibilities ranging from a Cold War-era nuclear bunker to a spaceship or even Noah’s Ark.

So far, no one from the City of Helsinki, HSY (Helsinki Region Environmental Services Authority), Helen, or telecommunications operators has claimed responsibility for the structure. While digging under an asphalt layer, workers unearthed a concrete slab measuring approximately three by two meters. The height of the structure remains unknown, and excavation has been conducted two meters around it without reaching its bottom.

Lauri Hänninen, the communications manager for the Kruunusilto project, expressed the significance of sharing an image of the “mystery object” as it sheds light on the challenges often faced in urban construction. Such surprises are common when digging, with Hänninen noting that uncharted pipes can appear, delaying progress as workers seek to identify ownership.

Typically, excavations uncover the foundations of old buildings, debris, bricks, concrete, and railway tracks. The Kruunusilto construction site has previously yielded unusual finds, including the discovery of an old elevator believed to be from either a former factory or a construction site in Merihaka, as well as a collection of horse bones from Siltavuorenranta.