To most, the question "What time is it?" is mundane. But to the men and women whom, over the centuries since 1675, have worked at the Royal Observatory, Greenwich it is of huge importance.
Evolving from an era when, in 1386 at the Salisbury Cathedral, the time was measured in quarters of an hour indicated by the gong of a bell, the atomic clocks of today are precise to one second in a million years. Fortunately for visitors to Greenwich, approximately 23 minutes east of Big Ben, dozens of artifacts from everything in between those extremes has been preserved.