This is the St. Martin Canal in Paris, somewhere near République, I think, where a lock takes it underground. The lock was used back in the day, when boats cruised the canal for both commerce and pleasure, and it's still functional. I don't know how often it actually gets used anymore, though.
You can see this very spot in the movie Amelie:
https://www.youtube.com/watch?v=T-kY7JEGrNI
I am not sure why but I absolutely love this image. Shade, greenery, water, engineering, symmetry.
We watched the locks open and shut for tourist boat last April.
The canal goes from Arsenal, the main pleasure boat port in Paris, to the port of La Vilette, and then to canals to the north. Not much used for commercials but mostly for pleasure boats and barges. A beautiful canal in the heart of Paris.