A skinny walkway crossing a mountain face above a gorge in Spain has been rebuilt and re-opened; it was closed in 2001 after five deaths, but people just wouldn't stop walking it. The new version has safety features and requires a helmet, but is still far too scary for most of us. DETAILS and heart-stopping pictures at the Telegraph (UK).
The walkway, called the Caminito del Rey, was originally built in 1905 for use by construction workers building a nearby dam. It's 3 km long and about one person wide. It got its name, King's Pathway, when King Alphonso XIII walked it in 1921 on his way to inaugurating the dam.
Photo below, looking up at the pathway, is from Wikimedia.