BBC News: Around 5,000 people, including hundreds of monks and lay followers from overseas, sit listening in a newly-built meditation hall.
Some have spent the night sleeping on mats, waking in the cold dawn to join the morning rituals.
Thich Nhat Hanh, a Zen master, peace activist and bestselling author, has spent the last four decades living mostly in France.
This is only his second trip back to Vietnam since 1966, when he went to the United States to call for an end to the war in his homeland.
He was then forced to live in exile after both South and North Vietnam refused to allow him to return.
In 1969, he led a Buddhist delegation to the Paris peace talks on Vietnam.
Today, he is back in Vietnam on a 10-week tour that is testing the limits of the …