Aerotruba is an incredible wind tunnel located not far from Moscow, measuring a whopping 13.5 ft (4.1 m) in diameter! With its two-level viewing deck, spectators and participants can both enjoy the immersive experience that this one of kind structure has to offer – with special thanks going out to Switzerland's Bodyflying AG for designing it back in 2009! This feat was made possible by Russian and Swiss engineers working together until finally passing certification as Russia’s first approved indoor wind tunnel year 2011 - what an accomplishment!