What a year this has been for This Big City! 2011′s 30th most popular post got more hits than 2010′s most popular post, so we’re going to run through the year’s 30 most popular articles, starting here with 30-21. Check back later today for 20-11 and the top ten.

30. Five Controversial Pieces of Urban Architecture

Is it even possible to introduce a new building to a city without some kind of controversy following? In this post I looked at five controversial buildings from across the globe, including one described as ‘a dying bird’ by unimpressed locals. Check them all out here.

29. Philadelphia Takes a Revolutionary Approach to Stormwater

In this post, Catherine de Lange looks at Philadelphia’s $2 billion, 25-year project which aims to not only reduce water pollution but transform much of the city’s infrastructure in the process. Read the article here.

28. Is this the Built Environment’s Best iPhone App?

Want to know which awesome buildings are nearby? There’s an app for that. Check out my review for Open Buildings on the iPhone.

27. Failed Architecture – London’s Worst Building

In this, one of my most controversial posts of the year, I take a look at 25 Ridgmount Street, a building which represents everything that is wrong with British architecture. Check out the comments – I appear to be alone in my hatred for this building.

26. The Groupon Approach to Public Transport in Cities

The way we get around cities has barely changed in half a century. In this article, Theodore Brown presents his vision for a new approach to public transport, one that is inspired by Groupon. Read the article here.

25. The Truth About London’s Cycle Superhighways – Part 3

Taking a cycle ride along London’s bizzarely short new ‘superhighway’, I come to the sad conclusion that ‘it really is three miles of blue paint and very little else’. Check out my photo essay here.

24. The American State that Scrapped Rail Investment and Built a Mall Instead

How’s this for an idea: let’s scrap a large investment in public transport but still subsidise a major mall development. This actually happened, which Theodore Brown reports on in this post.

23. Creative Use of Empty Buildings in Cities – An Interview with Specs Gallery

With so many buildings sitting empty in cities, there is incredible potential for creative reuse of space. Enter Specs Gallery – a community interest company in London who turned an office building into an exhibition space. Read my interview with Specs here. 

22. How London Tried and Failed to Become a Cycling City

Before the superhighways and cycle hire scheme, London invested in the ‘London Cycle Network’ – a seemingly comprehensive web of bike lanes across the city. But it failed to turn London into a cycling city. Read my article here.

21. How San Francisco Became a Cycling City Against the Odds

San Francisco has had a lot more obstructions than just its hilly terrain. Yet despite being legally unable to develop it’s bicycle network for 4 years, levels of cycling in the city have skyrocketed. Read my article here.