The girls have spent the past week climbing 2,500 metres up Machu Picchu in Peru in a bid to raise thousands of pounds for Coppafeel Breast Cancer Charity.
After making it to the peak, Ferne shared a rather impressive photograph of herself perched on a ledge and it's fair to say the view is simply stunning.
Commenting on the Instagram snap, she said: "10 thousand steps later & I made it to the top. Plus 5 days previous trekking.
"It was the toughest experience I have ever done in my life! I can officially say I have done something to be proud of #machupicchu & to add we, as a team, raised £55773.36 for @coppafeelpeople overwhelmed is an understatement."
Ferne also shared a picture taken from the plane as she began her long journey home to the UK.
"My view from my window, this almost doesn't look real. So long #peru," she said.
Meanwhile, Lydia has also posted several snaps, one of which shows her posing with walking poles. She told fans: "What a trip of a lifetime."
Writing alongside a more scenic shot, she added: "Goodbye Peru!"
Ferne and Lydia's loved ones have been quick to congratulate them on their impressive efforts.
TOWIE co-star Georgia Kousoulou tweeted: "@LydiaRoseBright you should be so proud of yourself my girl I can't wait to see you and hear all about it."
Lydia's boyfriend James 'Arg' Argent added: "2 more sleeps until we're reunited lol! God damn I miss @lydiarosebright and I'm lost without her!"
Good work, girls!
You can still sponsor Ferne and Lydia here!