While wandering the grounds of Gyeongbok-gung Palace, ("The Palace of Shining Happiness," built in the 1390's), I saw several teacher-led groups: kids on field trips in this Yi-dynasty city-within-a-city.

Here, they're gathered around a medieval bronze sundial. Students in Seoul have the past at their fingertips; taking a break from their smart-phones, looking back at how time was told centuries ago, their teacher explaining how the lines indicated the time throughout the year. Clocks like these were posted in public places; animal symbols were engraved around the edge for those who were illiterate.