One Direction is performing at Wembley Stadium all weekend for their Where We Are tour and thanks to Niall Horan we're feeling extremely nostalgic. The 1D member wrote a tweet pointing out that they were formed in Wembley arena and are now performing at the stadium for a series of sold-out shows.

After seeing Niall's tweet we felt the intense need to relive the day (July 23, 2010 to be exact) when 1D was formed. Click through to see 10 flashback pics from that day, then let us know which ones are your favorite in the comments below. Can you believe they've grown up so much since then?!

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