The annual secret pop-up picnic Diner en Blanc took place Thursday night on the steps of the Philadelphia Museum of Art.

For those who missed, or want to relive, the event, Inquirer photographer David Swanson's video takes you to the scene:

The concept, which started in Paris and has expanded worldwide, is now in its fifth year in Philadelphia.

Thousands of dressed-in-white diners attended the event, to which participants must bring their own table, chairs, utensils, napkins, meal (though catering is an option) and other picnic supplies.

Attendees meet at specified departure locations to the rain-or-shine event and are then taken to the secret picnic spot.

The already-memorable event even included a marriage proposal, CBS Philly reports. (This isn't the first time someone has chosen to pop the question at the dinner.)

Organizers say Philadelphia's Diner en Blanc, with about 4,500 participants last year, is the second-largest in the United States and fourth-largest in the world.

However, not all Philadelphians have embraced the event, which has prompted counter dinners, like 2014's Diner en Noir and Diner in Sweatpants.

Here are more scenes from the 2016 event:

A photo posted by Tracy (@mrskidd1013) on Aug 18, 2016 at 8:27pm PDT