On Saturday, September 12, 2026, Geodelta, together with Emmett Green and the Hollandse Cirkel Foundation, will open the doors of the iconic Geodesy Building at Kanaalweg 4 in Delft during Open Monument Day.
This historic building, constructed between 1892 and 1895, is a magnificent example of Neo-Gothic and Neo-Renaissance architecture and played an important role in the history of Dutch geodesy.
What can you expect?
- A tour of the building’s impressive tower
- An explanation of historical geodetic instruments
- A look inside the unique observatory
- View the sun through a special solar viewer (weather permitting)
Come by and experience this extraordinary monument in the heart of Delft!
Date: Saturday, September 12, 2026
Time: 10:00 a.m. – 4:30 p.m. (last entry at 4:00 p.m.!)
Location: Geodesy Building, Kanaalweg 4, Delft
More information: Delft Open Monument Day
