Stockholm knowledge – You can visit the longest art gallery of the world in Stockholm. It’s located underground in the subway stations and the art stretches over about 110 km (68 miles)! It’s all over the walls, ceilings and sometimes even the floor in different constellations for every station. What type of octopus is the longest in the world?

1 – Seven arm octopus
X – Giant pacific octopus
2 – Frilled giant pacific octopus