Postcard from De Bildt
The KNMI, Koninklijk Nederlands Meteorologisch Instituut (Royal Netherlands Meteorological Institute) in De Bilt (spelled De Bildt on the postcard).
The institute, founded in 1854, moved to De Bilt in 1897. The postcard was sent in 1906, so the observatory was still relatively new then. The KNMI is still in De Bilt. They research climate change and seismology, but in The Netherlands they are best known for their weather forecasts.