Sewer cover of the Koninklijke Nederlandse Grofsmederij

The Nederlandse Grofsmederij was an iron works company, located in Leiden, which didn't survive the big shake-out of the manufacturing industry in the 1970s. It was founded in 1836 by a Dutch-Frenchman William Archibald Bake who (amongst other things) fought in the Russian campaign of Napoleon.
In its heyday it employed around 700 men.

Here is a picture of the workshop of the Grofsmederij:
www.flickr.com/photos/95306653@N00/2212827614 /

Grofsmederij is a composite noun consisting of "grof" meaning coarse or rough, opposite of fine, and "smederij" meaning smithy or foundry. So the company made the big stuff, not fine ironwork. "Kon." is an abbreviation of "Koninklijk" meaning royal. Dutch companies which exist over 100 years can be bestowed with this title. It does not bring direct benefits, but it may help in marketing, exporting stuff etc.