Prague's Astronomical Clock, the Orloj, has been running since 1410, making it the oldest working example anywhere. It tracks the hours, the zodiac, sunrise, sunset and the phases of the moon, though it cheerfully ignores daylight savings and spends every summer an hour behind.

Legend has it that Master Hanuš, the clockmaker, was blinded by town councillors who didn't want a rival city to have one like it. He climbed the tower, felt his way to a secret lever, stopped the clock, and died shortly after. It sat silent for a century.

The hourly show, in which twelve apostles parade past a bell-ringing skeleton, lasts roughly twenty seconds and has been voted the second most disappointing event in Europe, just behind the Mona Lisa.

VoiceMap's self-guided audio tours decode the dials, retell the Hanuš legend where it happened, and place the Orloj within the Old Town Hall's longer history.