Silence in the city

An exterior door, a vestibule, another door, and then a silent space where light fell in from above. The small buildings appeared in several cities, more or less simultaneously. Always on an inconspicuous place; never on the middle of a square or overtly visible. Sometimes they relocated. That also explains why it took some time before people ascertained the existence of these silent spaces; constantly the same design, simple and self-evident. The door was opened in the morning and closed at dusk. It turned out that silence in the center of town attracted ever more visitors. Nobody talked about the reason why.