Yalda, a traditional Persian festival, is the celebration of the longest night of the year.
To use technical terms :cool:, Yalda is the eve of the Winter Solstice in the Northern Hemisphere which usually occurs on 20 or 21 December each year.
Yalda Night is still celebrated by many Persians around the world. Here are some photos of Yalda shopping this year in Iran:
From Fars News Agency:
From Mehr News Agency