Our cities are filled with buildings, roads, cars, buses, trains, bikes, parks and gardens. They are crisscrossed with power, water, sewage and transport systems. They are built by engineers, architects, planners, technologists, doctors, designers and artists. Our cities are shaped by our environment, our society and our culture. And each and every part is built on mathematics.

You can join Plus author and Charles Simonyi Professor for the Public Understanding of Science, Marcus du Sautoy, on a mathematical adventure in the city. Marcus and his team of mathemagicians are constructing walking tours of the city — but they need your help!

With 500 days to go everyone here at the MMP is getting very excited about the 2012 Olympic and Paralympic Games. In July 2012 medals will be won, records broken and stories of triumph and tragedy will be told — and here at Plus we are looking forward to revealing the mathematics behind them.

Rising like a giant pringle from the Olympic Park construction site, the Velodrome is the first of the 2012 London Olympic venues to be completed. With its sweeping curved roof and beautiful cedar clad exterior the Velodrome is a stunning building. But what most of the athletes are excited about is the elegant wooden cycle track enclosed inside, the medals that will be won, and the records that might be broken, in the summer of 2012.

Today is Pi day - it's March 14th, written as 3/14 in the US - and to celebrate we bring you some of our favourite Pi articles:

A massive earthquake hit Japan earlier today, registering 8.9 on the Richter scale and the largest ever recorded for Japan. The tsunami triggered by the quake brought a 10m high wall of water in northern Japan, and other countries are now waiting for it to hit their shores.

But what causes earthquakes and tsunamis and what can we do to protect ourselves from their destructive power?

When you try to put democracy into action you quickly run into tricky maths problems. This is what happened to Andrew Duff, rapporteur for the European Constitutional Affairs Committee, who was charged with finding a fair way of allocating seats of the European Parliament to Member States. Wisely, he went to ask the experts: last year he approached mathematicians at the University of Cambridge to help come up with a solution. A committee of mathematicians from all over Europe was promptly formed and today it has published its recommendation.

To coincide with the 100th International Women's Day two new competitions to find the best young female mathematical minds in the UK and Europe have been launched.

Almost nothing tangible remains of the legendary Bletchley Park codebreaker Alan Turing. So when an extremely rare collection of papers relating to his life and work was set to go to auction last year, an ambitious campaign was launched to raise funds to purchase them for the Bletchley Park Trust and its Museum. The Trust has announced today that the collection has been saved for the nation as the National Heritage Memorial Fund (NHMF) has stepped in quickly to provide £213,437, the final piece of funding required.