Wallenberg, also known as the Wallenberg Four, is located at the Wallenberg Traditional High School in San Francisco, California.
It is a popular gap among the skateboarding community and measures 6 feet high and 22 feet and 6 inches long.
The Wallenberg gap first appeared in Mark Gonzales's part in "Video Days," a 1991 skateboarding video released by Blind Skateboards. More recently, Thrasher skateboard magazine hosted "High Noon at the Big Four" at the famous spot. Unlike traditional skateboarding competitions, there were no rankings or standings; the 2004 event was billed as a "big tricks contest." In order to encourage skaters to attempt difficult tricks, cash prizes were offered for landing specific ones. On May 30, 2009, a contest was held at Wallenberg, in which almost a dozen tricks were landed. Andrew Reynolds was the first skateboarder to successfully perform a frontside flip and backside flip. Chris Cole was the first one to 360 flip it in New Blood a skateboarding video by Zero Skateboards. Some of the most popular skateboarding tricks that have been performed include Frank Gerwer's kickflip over the set. Darrell Stanton performed a switch backside 180 at the Thrasher contest, Lindsey Robertson of Mystery Skateboards performed a backside heelflip over the gap at the Thrasher contest. He also landed a heelflip over the set at the 2004 contest. Danny Gonzalez performed a kick flip to Melon grab in Transworld's "The Reason", Elissa Steamer attempted an ollie which, if landed, would have made her the first female skateboarder to land an ollie over Wallenberg. Some other tricks include a backside 180 (Diego Buccheri), a pop-shove it (by Steve Nesser - 411VM #66), a switch ollie, a switch frontside 180 (by Tony Manfre - montage in Free Your Mind from Transworld Skateboarding), a pop-shove it to melon grab (Jeremy Reeves, from footage featured on Thrasher Magazine's website). While the stair set is still there the school has re-profiled the "run up" to the set so it is no longer possible to use Vega St to gain speed, it has to be obtained from a ramp or roll in, or by gaining speed in some other form. Also recently landed were Jordan Hoffart's Varial Heelflip, Nick Merlino's Switch Heelflip, Chris Cole's B/S 360 and Switch F/S Flip, Cody McEntire's B/S BigSpin (also attempted Nollie BigSpin), Andrew Pott's Hardflip, and Lizard King's 180 Ollie North, Ollie Disaster, and Airwalk at the recent Thrasher Magazine's Back to the Berg 5/30/09 contest. Also Tim Carr Nollie 360ed it on February 19th 2010. Adding yet another amazing feat to this massive stair set.