There are two nude beaches in Warsaw. The so called gay beach is on the Praga side of the Wisla River. The so called family beach is on the Warsaw side.
It is best to use the google maps and search the street name shown in this video to find the beach. Then go to satellite view.
These places are really not that popular. People prefer to go to the beaches on the Baltic. See our other videos on them. You can find those videos through the link in the first paragraph of this note.