Amazing Hacks & Wondrous Gadgets Thread?
When the Basque city of San Sebastian decided to reroute a railway line, it was left with an unused tunnel. Rather than close it off, city planners came up with the idea to turn it into a bike underpass that now connects the Amara and Ibaeta neighborhoods. The two areas were previously impassable by bike and, upon opening in 2009, the tunnel served to promote cycling among commuters and students. It makes up just over half a mile of a mile-long bikeway, which also has open-air sections framed by verdant vegetation.