Watch: 2016 Diner en Blanc at the Art Museum steps

Katie Filpus (from left), of Chestnut Hill; Rusty Prochnow, of Freehold, N.J.; and Cathy Waugh, of Philadelphia, wave their napkins at Diner en Blanc on the Art Museum steps and surrounding area Thursday, Aug. 18.

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:

Swanson video.

Swanson video 2.

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

As always, the location was a secret until the last minute. In other recent years, the dinner has been held at the Navy Yard, on the Avenue of the Arts and on the John F. Kennedy bridge near 30th Street Station.

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.

Swanson video 3.

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:

Ready for dinner!#dinerenblancphilly #debphl16 #rockysteps #philadelphiaartmuseum #dinerenblanc2016

A photo posted by Melissa�� (@curlywithatwist) on Aug 18, 2016 at 8:04pm PDT

Dîner en blanc Philadelphia was a raging success! #debphl16 #dinerenblanc #philadelphia

A photo posted by Kristin (@phillykfo) on Aug 18, 2016 at 8:58pm PDT

A Thousand Points of Light #debphl16 #DinerEnBlanc #whyilovephilly #peopledelphia

A photo posted by Christian (@tempusedaxrerum) on Aug 18, 2016 at 8:55pm PDT

Diner en Blanc #debphl16 #philly #dinerenblanc #artmuseum #vip

A photo posted by Jess DeGore RD LDN (@dietitianjess) on Aug 18, 2016 at 8:46pm PDT

The set up is so well orchestrated. #debphl16 #dinerenblanc

A photo posted by Kristin (@phillykfo) on Aug 18, 2016 at 8:37pm PDT

#debphl16

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

#DEBPHL16

A photo posted by Caitlin Bonfig (@giggleypuff) on Aug 18, 2016 at 7:38pm PDT

#debphl2016

A photo posted by Ashlie �� Nawrocki (@shlia_bia) on Aug 18, 2016 at 5:24pm PDT

Me and my mom at Le Diner en Blanc 2016 #dinerenblanc

A photo posted by Eric Barnaba (@eric_the_bald) on Aug 18, 2016 at 4:50pm PDT

Diner en Blanc #philadelphia #dinerenblanc

A photo posted by Kate Matheson (@k8tem13) on Aug 18, 2016 at 5:09pm PDT