Where drum towers set life's tempo

Yang Yuanju's family offers ritualistic sacrifices to their ancestors in a 19-story drum tower in the village center on Chinese Lunar New Year's Eve.

The buildings - constructed with notched boards and not a single nail - are central to ethnic Dong life in every sense. They're the anchoring landmarks that soar over every settlement - even the tiniest hamlet.

It has been this way since time immemorial. Nobody knows when the ethnic group erected the first. Their language is without written form.