Human Checkerboard
"Praha, Czechoslovakia - Models of precision and accuracy, thousands of youngsters make up this geometric pattern as they stand stiffly at attention in a Sokol exercise in the stadium here during ..."
“… the Slet, or exhibition, that draws spectators from all over the world. On this occasion, June 19, 170,000 persons packed the stadium to watch the show.”
Every Czech loves a good Sokol. June 19, 1938.
My parents are/were from Prague. My dad would have been 4.
Sitting here now watching over him after he had a stroke 3 months ago (took 2 shots before I talked him out of more).
After some prompting he says he participated more than once. A little more questioning yielded it was age 15'ish, maybe younger.