The author of this image from Switzerland is unknown, and the image was published at least 70 years ago. It is therefore in the public domain in Switzerland by virtue of Art. 31 of the Swiss Copyright Act.
Note that this applies only if a reliable source is cited to indicate that the author is not publicly known; just not knowing who the author is is not enough to qualify the image as public domain. This image may not be in the public domain in countries other than Switzerland.
This is a featured picture on the Arabic language Wikipedia (صور مختارة) and is considered one of the finest images. See its nomination here.
If you think this file should be featured on Wikimedia Commons as well, feel free to nominate it.
If you have an image of similar quality that can be published under a suitable copyright license, be sure to upload it, tag it, and nominate it.