The art hidden inside ordinary looking bollards in Cardiff's city centre A hidden world is tucked away in these ordinary-looking metal bollards Updated The video will auto-play soon8Cancel Play now You've probably walked past them hundreds of times without even taking a second glance. On The Hayes in Cardiff stand several metal bollards which look just like all the others in the city centre. But if you take a closer look, you'll find incredible pieces of art hidden inside. You might feel a bit odd stopping and bending down to peer into one of the bollards. But if you do, you'll be treated t...