Rotterdam is known for its impressive skyline filled with skyscrapers. However, there is also a lot of architecture underneath the city. Often just as impressive, but just not that well-known. During the Rotterdam Architecture Month we celebrate these hidden gems of Rotterdam. These four icons are definitely worth a visit:

Nuclear shelter beneath the post office
Not many of us know that near Rotterdam’s City Hall, there is a completely functioning nuclear shelter underneath the former post office on Coolsingel. It was built in 1975 when the threat of the ‘red danger’ seemed very real. The former PTT (Dutch national postal company) built these kinds of shelters throughout the Netherlands. Fun fact: the basement in Rotterdam is an exact copy of the one that would have secured the Dutch royal family in case of an emergency.

Underground tram stop in the south of Rotterdam
When the metro started to head to the south of Rotterdam in the 1960s, there was only one tram left in this part of town: Tram 2. During rush hour, Tram 12 would also run to cope with all the commuters. It is remarkable that this tram route had its own tunnel underneath the ‘Groene Hilledijk’. It even had its own stop called ‘Randweg’. This tram stop was opened in 1969 and almost thirty years later, in 1996, the tunnel was closed. Turned out the tram stop in a tunnel wasn’t the safest way to travel (you think?). Luckily this underground tram stop still exists, graffiti and all, seeing as it might be the most unique one in the Netherlands.

Technical Cathedral underneath the Erasmus Bridge
It’s a very graceful structure, our Erasmus Bridge. If you see the bridge opening, it looks as if the pavement lifts itself ever so gently. Yet there are enormous forces that enable the bridge to open, it’s quite an accomplishment! Part of what makes it look so easy, is the gigantic counterbalance that stands in a huge basement underneath the bridge: the bascule basement. In this underground ‘technical cathedral’ everything literally revolves around a weight of no less than 1,050,000 kilogrammes or 1,050 tonnes.

TIP: Take a tour to the bascule basement during the Day of Architecture and find out all the ins and outs about how the Erasmus Bridge works.

The Time Stairs underneath the Market Hall
Rotterdam originated at a dam in the river Rotte. This is the very same spot where the Market Hall stands today, which we can proudly call one of the most modern buildings in the Netherlands. When the Market Hall was being built, extensive archaeological research was done to discover more about our history. The findings were preserved and are now on display for the general public at the Time Stairs. You can literally descend into the parking garage and travel through our history, with all the archaeological findings there to admire.

TIP: Curious about the underground world in Rotterdam? You’re not alone! Parfum de BoemBoem is fascinated by what happens below street level. You can go on a tour to explore the underground world of Rotterdam, taking you to the most exciting places. During the tour you’ll experience several performances, like music, dance or poetry.