Movie: in our next exclusive movie with Julia Peyton-Jones, the Serpentine Gallery director discusses the artificial mountain MVRDV proposed for the 2004 Serpentine Gallery Pavilion, which eventually proved too expensive to build.

Since the Serpentine Gallery's pavilion programme began in 2000, the gallery has built a new structure on its lawn in Kensington Gardens every year except one.

In 2004, Dutch architecture firm MVRDV was invited to design a pavilion, but the huge artificial mountain they proposed to construct over the gallery was never built.

"I think of it as a heroic failure on all parts," Peyton-Jones says in the movie. "They wanted to put a mountain over the Serpentine, so from the outside you couldn't see it at all."

"It was incredibly expensive. In addition to that, the health and safety considerations were enormous. So regretfully – very regretfully – we decided it couldn't go ahead."

Despite never being built, Peyton-Jones believes MVRDV's design is still a significant contribution to the gallery's pavilion programme.

"It underscores that some projects in architecture don't happen," she says. "We didn't have a pavilion that year but that's OK and I've always felt that it is OK."

"We keep it in the run of the commissions, partly because my own investment of time was so significant that I feel it has to be there. Partly because the scheme was extraordinarily well worked up. We worked on it really hard."

Visitors would have been able to walk up and down MVRDV's proposed structure, as well as entering inside to visit the gallery within it.

"MVRDV were the youngest practice that we had commissioned up to that time and they came up with a scheme that was amazing and brave audacious and grand," Peyton-Jones says. "It was the first time that the architects really wanted to obliterate the gallery."

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"They are very distinguished architects, so I'm proud they are part of the project. I'm disappointed that we couldn't do it, but that's how architecture is."

This movie was filmed by Dezeen at the Serpentine Gallery in London. All images are by MVRDV and courtesy of Serpentine Galleries, unless otherwise stated.

Dezeen is looking back at each of the pavilions from 2000 to 2015 in a series of movies. You can watch all the movies as we publish them on our YouTube playlist: