Ironically, airports are one of the few things you often don't get to see an aerial view of since you don't get a cockpit seat. Here are a dozen of our favorites, purely in terms of their abstract graphical layout. See if you can guess them.

I've picked the most interesting selection I could find from the worlds largest gatherings. The largest anti war protest was in Rome in 2003, against the Iraq war, where more people gathered than for the annual pilgrimage to Mecca, the Haj. In fact, Sao Paulo's Gay Pride festival is roughly the same size as the Haj, with 2.5 million attending in 2006 and the Haj isn't even necessarily the largest gathering in Islam, with 14 million people attending the Shiite Arab'een in Iraq. Religious ceremonies dominate, with a Papal mass in Ireland in 1979 resulting in a third of the population (1.25M) gathering in a single field, but paling in comparison with religious gatherings in India, including the Kumbh Mela which drew an unbelievable 60-70 million people over 45 days in 2007, making it the largest gathering in history.

Yesterday we managed to get into CERN and do some exploring. Our mission? Not to go to the Giant LHC experiments, such as Atlas, but to root around the campus itself, find the exact place where Tim Berners Lee invented the web, marked by a small plaque, and photograph it, license-free, since there seem to be no images of it that we could find. We went through several doors marked ‘radiation’, were told to leave one place, because ‘the beam was on’, saw the Grid data center and rooms with blackboards covered in equations – but we found it.

Kowloon Walled City (KWC) was a 10-16 storey monolithic 6.5 acre city block in the flight path of the old Hong Kong airport, that housed somewhere between 35,000 and 50,000 people when it was finally demolished in 1993. 30 times the density of Manhattan with no streets and little daylight, it was a rat infested, cockroach ridden filthy labyrinth. KWC was a no-man's land that fell neither under British Jurisdiction nor Chinese, where Hong Kong's appetites for the 3 vices: prostitution drugs and gambling could be satiated, but where ordinary families lived alongside nearly 800 factories and shops. It had 161 unregulated doctors and dentists along with food producers from whole pig roasters to the suppliers of most of Hong Kong's fish balls. Most of the people that lived in KWC never left.Dozens of sites have covered KWC before (as have we), but its such a strange and unusual Oobject that we've trawled through hundreds of sites to try a pull together a list of our favorite images and links which succinctly describe it.

Whenever you see a picture of the ancient pyramids of Giza the view behind is of endless sweeping sands rather than the smog heavy skyline of downtown Cairo. Here we’ve collected some of the least flattering and depressing views of famous monuments or places, from the Stonhenge car park to the Starbucks in the Louvre. There are a couple of unlikely ones such as the Acropolis which in some ways is depressing from every angle, having been destroyed while used as a munitions dump, or the more preserved version of Trajan’s column which is hidden away in a London museum, with a janitor’s closet in its base. Vote for the worst.

From Tampa to Dublin to Alicante and Dubai empty condos and villas that were never home to anyone, litter the landscape as a sterile reminder of a party that never was. But perhaps the biggest housing bubble of them all has just been popped – deliberately by the Chinese government who saw that Shanghai and Beijing real estate increases were unsustainable. Over the last month, Beijing housing prices have fallen at a unbelievable 377% annualized rate, possibly heralding part III of the Great recession following the US banking collapse and European sovereign debt crisis.The most dramatic pictures in this collection are of the empty Chinese city of Ordos, which is a piece of government led, speculative development on a scale unimaginable elsewhere. An entire city waiting to be occupied. Ordos is not a failure yet, but if it is, it will be emblematic.

American monuments hit the sweet spot between being young enough to have been photographed while being built, but old enough that few people can remember them not being there. Because of this an entire legacy can be viewed as it was while it was being created. From the D.C Capitol building, which ironically, slaves helped to build during the Civil War, to the Statue of Liberty, which was built in France, the forgotten train Grand Central train shed, the Empire State building when it was two storeys high or the Hollywood sign before it read Hollywood, here are our picks of America’s most famous monuments while they were being built.

New York, a city which is defined by its skyline, existed as a metropolis well before skyscrapers and has gone through several distinct architectural phases.I’ve picked this collection to demonstrate these, from the earliest known photograph of New York in the 1840s which shows the Upper West side as rural, to the Brooklyn Bridge dominated skyline of the mid nineteenth century.A postcard from 1904 is labeled ‘New York Skyscrapers’ but shows very few of what we would call skyscrapers today, consisting of the early steel framed buildings epitomized by the flatiron.Between the 1920’s and 1930’s the machine age skyscraper city of masonry-clad, art deco splendor grows at breakneck speed and remains similar in texture until the emergence of curtain wall, glass and steel buildings in the 1950s, after the completion of the Seagram in 1958.The 1973 opening of the iconic World Trade Center coincides the building of other inferior block like buildings along the periphery of lower Manhattan, notably at Water St., which destroy the hill like collection of spires.

As technology companies oozed slowly from San Jose to San Francisco, the architecture morphed from purely university campus, to a hybrid between this and a South of Market warehouse, complete with loft living accoutrements such as foosball tables. The new Facebook HQ is a perfect example of this, looking something like a Wholefoods, whereas Google looks more like the place full of plastic balls that you leave your kids when shopping at IKEA.

The view straight down from a bridge tower, a skyscraper creates a perspective which we looks surprising. Cars look like models and the base of something like the Eiffel tower looks tiny and distorted. That and the fact that these views are absolutely terrifying. Here are a dozen of our favorites.

Trainspotting declared the worst toilet in Scotland, something which presumably takes some beating. Here are some of the worst toilets, kitchens, living rooms and bedrooms.

Perhaps not just a video game cliche but a movie, TV series and theme park one too. Ever since WWII’s pacific theater included remote jungle areas in the tropics, the image of a crashed plane, rotting in the jungle, covered in vines and terrifying critters has become an archetypal image of remoteness and abandonment.Anyway – we’ve dug out a list of real life planes hidden in jungles, including one fake one for good measure.

Despite the appearance of permanence that historic buildings create, many if not most of the worlds famous cities have been almost entirely destroyed either by war, property speculation or Ayn Randian architects. They have been rebuilt, either as replicas (Warsaw) or even in the image of the culture that destroyed them (Hiroshima). Here are images where either we or others have matched up locations for incredible before and after shots.

The original British Secret Service headquarters was just that, secret. But the increase in importance of electronics meant that it was more important for a building to be invisible to electronic eavesdropping. as such the current M16 HQ in London is about as obvious a giant sign saying 'secret building here', yet it is enclosed in a giant Faraday cage to protect its communications.Not all Intelligence agencies have had a discrete architectural past, Franco's House of Screams, or the Soviet Lubyanka are demonstrably terrifying. Mossad's HQ, until the 60s or the current Australian Secret Intelligence Service look quite modest compared to the hardly known Ministry of National Security of Azerbaijan, which houses its intelligence service, in a large and monolithic building of dramatic proportions.

This year the MIT class ring, the Brass Rat, hides a hackers' diagram of a subterranean campus wide tunnel network.Networks of secret passages and tunnels have been built on a giant scale, from components of the Maginot line to the Viet Cong Cu Chi Network. Others perform a peacetime function, such as the half mile tunnel network H.G. Dyar built under his Washington home, as a hobby, the passageways under Disney's Magic Kingdom or the unbelievable 5000 year old Lizard People tunnel network under Los Angeles that the L.A. Times published a diagram of during the depression.Here is a collection of our favorite tunnel network diagrams, drawings or models.

Despite the title of this list, several of these housing projects were designed by some of the world’s most famous architects and lauded at the time. The undeniable squalor of 19th Century slums combined with modernism to produce and attempt to clean things up and create a crystalline utopia. The end result was often an anti-septic vision of hell, a place devoid of organic spaces and evolves social interaction.The architectural crime that started with Corbusier’s insane proposal to demolish the historic center of Paris and replace it with something like the worst of the South Bronx and culminated in the White and Black racially segregated human silos of St Louis's Pruitt-Igoe, continues to this day and even as middle class, owner-occupied dwelling such as those in Hong Kong. Its principal feature is de-humanizing alienation. Vote for your worst…