The National Shrine of Our Mother of Perpetual Help in Baclaran, Paranaque, Philippines is the biggest shrine in the world dedicated to Our Mother of Perpetual Help. Every Wednesday throughout the year, up to 150,000 devotees flock to the shrine. Although Wednesday is the climax of the week, the rest of the week also shows a perpetual influx of people in the shrine day and night. Thus, the shrine is open 24/7. This is the so-called Baclaran phenomenon.Baclaran can be regarded on equal putting with famous international shrines and pilgrim churches in the world like Lourdes in France, Fatima in Portugal, Assisi in Italy and Guadalupe in Mexico. Five to ten million devotees, visitors and tourists visit the shrine throughout the year. While it may not enjoy the fame of other great Marian shrines around the world, Baclaran stands second to none in the multitudes who express affection to Our Mother of Perpetual Help.

 

There are many factors behind the Baclaran phenomenon. There is its history, the architecture, the Redemptorist missionaries, the devotees , the lay volunteers, mission partners and many others.
(http://www.baclaranchurch.org/home.html)