While Walter Gropius was known for his architectural designs and contributions to modernism, he was not primarily a painter. He did create some sketches and watercolors, but they were mainly tools for his architectural work, not finished art pieces.
If you're interested in seeing Walter Gropius's work, you'll find his architectural masterpieces around the world, such as:
* The Bauhaus Building in Dessau, Germany
* The Gropius House in Lincoln, Massachusetts
* The Harvard Graduate Center in Cambridge, Massachusetts
You can also find his sketches and drawings in museum collections and archives, including:
* The Bauhaus-Archiv Museum in Berlin
* The Museum of Modern Art (MoMA) in New York City
* The Harvard University Archives
To find specific works, you can search online databases like the Getty Research Institute or the Smithsonian Institution Archives.
However, if you're looking for paintings by an artist named Karl Wilhelm Gropius, it's possible he existed, but he is not a well-known figure in the art world. You may need to do further research to find any information on his work.