An underground tunnel called Opintoputki at the University of Helsinki metro station was reopened to passengers on Wednesday after a long renovation. Opintoputki is a tunnel that leads from Yliopistonkatu in Kluuvi to the ticket hall of the metro station. During the renovation, an artwork called Kenno by artist Kirsti Taiviola was also installed in the tunnel. The light-artwork is made with specially made luminaires that direct the light produced by LEDs through hand-blown glass lenses. These project a honeycomb pattern on the ceiling and walls of the tunnel.