The 9th January 2013 is the 150th anniversary of the London Tube, or underground – choose your term!

The BBC has a neat slideshow of how the tube map has evolved over the years. Transport for London (TfL) are organising a range of activities to celebrate the anniversary.

The London underground map is used daily by thousands of commuters, visitors and tourists to London to help them navigate the network. This would not have been as easy if the original tube map was not designed by Harry Beck in 1931.

The concept of the tube map is also used in portfolio management circles, most notably by Craig Kilford in his Portfolio Journey concept.