The entry free at the Marble Arch Mound is being scrapped in August after disappointed visitors criticised the attraction, with one saying it was "the worst thing I've ever done in London".
The 25-metre mound was meant to give views of the capital’s Oxford Street, Hyde Park, Mayfair and Marylebone.
But just a day after it opened, parts of the man-made mountain were "not ready for visitors", Westminster Council admitted.
"We wanted to open the Mound in time for the summer holidays and we did not want to disappoint people who had already booked tickets," the council said.
"We made a mistake and we apologise to everyone who hasn’t had a great experience on their visit.
"With that in mind we’re going to make The Mound free for everyone to climb throughout August.
"Now is the time to bring the buzz back to central London and to see people visiting the West End again.
"We are working hard to resolve the outstanding issues and create an attraction worthy of our fantastic city," the council added.
The Mound which cost around £2m to build was part of a scheme to increase the number of people visiting the West End as lockdown restrictions eased.
"Ticketing operator SeeTickets will be in touch those who had already booked tickets for August to offer a refund and a free return visit," the council said.