No geography trivia quiz this week (still looking for ideas in case anyone has any). Instead, a different kind of challenge:
What are these?
UPDATE: After a dozen interesting guesses, Pascal gets it right: They’re metro turnstiles.

A sea of old turnstiles behind a gate at Pie-IX metro

Turnstile innards, with unrelated celebratory horn
These photos were taken at the Pie-IX metro station, where dozens of the old turnstiles have gone to die. They have been replaced by new Opus-enabled turnstiles, except for the one at each station that was kept for transition purposes (those will be joining them soon) and some exit-only turnstiles that don’t need to be replaced.