This building may look like a historic residence or a castle, but it actually is a giant water reservoir. Constructed between 1913 and 1918 following the architectural plans of Gustar Améen, the Vanadislunden water reservoir was built atop an earlier reservoir from the 1870s. It has a castle-like design with four corner towers, and the facades are built with red Helsingborg bricks on a sturdy granite base. The tall stone base represents the outer walls of the old reservoir. The roofs are covered with black glazed roof tiles.
Within the fortress-like walls lies a pool which is 6 metres deep and holds approximately 8,100 cubic metres of water. The pool is made of concrete and stands on pillars inside the older reservoir. The highest water level is 54 metres above the city's zero point, and the reservoir effectively ensures the functionality of the surrounding pipelines.
In April 1954 Vanadislunden reservoir made major headlines in the Swedish news, such as "The Deluge from Vanadis Water Tower," "Traffic on the Streets Stopped," and "Feverish Children Rescued via Ladders" (referring to the evacuation of an orphanage). The water reservoir sprung a leak, and eight million litres of water gushed into the neighbourhoods surrounding Roslagstull. The cause was a cast-iron valve at the bottom of the new reservoir that burst, causing the contents of the pool, which was nearly full, to pour out. The staff at the facility had no way to prevent the incident. However, the flow of water was somewhat slowed down by the outer walls of the old reservoir, which could withstand the pressure. As a result, the damages were moderate, although some cars ended up partially submerged in the water. The traffic was halted, an orphanage had to be evacuated, and hundreds of basements were flooded.
Vanadislunden reservoir is in use today. It is therefore closed to the public but you still can admire the impressive structure from outside.
Sources: Atlas Obscura, Wikipedia
