This card shows the amazing (although not very old) Cathedral of Saint Bavo in Haarlem. I haven't been there (actually, I've visited only Amsterdam and a few other towns in the Netherlands, mostly at the seaside). According to the sender, this church is the biggest building in Haarlem.
The Cathedral of Saint Bavo, was built in Haarlem, the Netherlands by the Catholics from 1895 to 1930 to replace the former Waterstaatskerk St. Joseph. That church was itself a replacement for the Sint-Bavokerk, that had been converted to Protestantism from Catholicism in 1578. The Cathedral of Saint Bavo now serves as the main cathedral for the Catholic diocese of Haarlem. Within the Cathedral, the former sacristy has been converted into a small museum (schatkamer) containing historical artefacts from Haarlem's Catholic past.