The Bridgeman family, from Fallodon, near Alnwick, climbed Ben Nevis in Scotland, Scafell Pike in the Lake District and Snowdon in Wales in the space of 24 hours.
Orlando (20), Ned (19), Ida (17) and Ben (14) did the walking while their parents, Mark and Lucia, did the driving.
Their effort coincided with a mini-heatwave.
“Watching the sun set on the way down from the summit of Ben Nevis and then rise again, over 250 miles away, when we were walking up Scafell Pike was incredible,” they said.
They have raised £4,800 for HospiceCare North Northumberland, which looked after their grandfather at the end of his life, and Young Minds which raises awareness of mental health issues and campaigns for better services for the emotional well-being and mental health of children and young people.