A couple staying on the 40th floor of The Shard woke up to a surprise at 6am this morning - a man climbing past their window after scaling the skyscraper barefoot.
Paul Curphey, 52, and partner Treasaidh, visited the iconic structure in southeast London for a birthday trip when they noticed someone "waving at the window".
Earlier free-climber Adam Lockwood shared a selfie on Facebook standing precariously close to the edge of the iconic 310m (1,016ft) building.
Mr Lockwood has shared a number of escapades on his profile, including pictures at the top of Dubai's second-tallest building, Marina 101, which measures 425m (1,394ft).
Mr Curphey, a retail businessman from the Isle of Man, snapped a picture of a man who he said was "yelling in a celebratory fashion".
"He appeared, waving at the window, 40 floors up, already in the deep end so to speak.
"We couldn't help but urge him on to complete his mission.
"He was smiling, waving, and having the time of his life."
"(My) partner thought I had pulled all the stops out and managed to get a guy to bring a box of Milk Tray for her birthday," Mr Curphey joked.
"It was scary to see, but his happy demeanour was amazingly uplifting," he added.
Following the incident, the Metropolitan Police said a 21-year-old man has been arrested on suspicion of trespass.
Two other men were arrested on suspicion of causing public nuisance during the incident.
The force arrived at the scene, close to London Bridge, around 5.38am on Sunday morning, joined by the London Ambulance Service and London Fire Brigade.