The Inco Superstack is the tallest chimney in the Western hemisphere. Wikipedia says:

The Superstack sits atop the largest nickel smelting operation in the world at Inco’s Copper Cliff processing facility in the city of Greater Sudbury. It was constructed by Inco Limited in 1972 at an estimated cost of 25 million dollars. The 1,257 foot (381 m) structure was built to disperse sulphur gases and other by-products of the smelting process away from the city itself. As a result, these gases can be detected in the atmosphere around Greater Sudbury in a 150 mile radius of the Inco plant.

150 miles doesn’t seem all that surprising when you see the vast plume of fumes extending Northwards.

Thanks: Ian

You can never find a taxi when you need one and at JFK airport that’s because they’re all hiding in a four acre sea of yellow known as the Central Taxi Hold. According to the New York Times the drivers wait here for up to five hours at a time, playing football, dominoes or backgammon. Apparently it’s worth the wait though as the drivers earn a $45 flat fare to Manhattan.

Thanks: Jon Abad

Very close to each other near Walnut Grove CA, are three utterly enormous communication towers. Firstly is the Channel 40 Tower which stands at 608.7 metres, then just a little South is the Hearst-Argyle Tower which stands at 609.6 metres (there’s actually 17 communication towers in the US at exactly 609.6 metres, presumably they’re all just the same kind?).

Finally we have the KXTV/KOVR Tower, an absolute behemoth of communications towers. Standing at 624.5 m the structure is taller than the CN Tower, and officially the 3rd largest structure in existence (the first two aren’t covered by hi-res images on Google yet). There’s loads more of these towers across the US, but they all start to look kind of the same after a while…

Thanks to Josh Kaplan.

Home of the Seattle Mariners baseball club, the Safeco field has a retractable roof, which was open on the day of this photo. Just to the north is Qwest Field, a football stadium home to the Seattle Seahawks and Seattle Sounders.

The two fields were built to replace the Kingdome, which was demolished in the world’s largest implosion of a single concrete structure on March 26th, 2000.

Thanks: Braz & many others

Kennywood Park is Southwest Pennsylvania’s amusement park, and was known as the “Roller Coaster Capital of the World” in the 1970s for its collection of excellent wooden coasters. Scott Ventura (who seems to know quite a bit about this park!) gives us the guided tour:

Due to Pittsburgh’s hilly terrain, two of the coasters are able to drop into valleys without first ascending a lift chain. When built in the early 1990s, the Steel Phantom had to longest drop in the world at 220 feet, topping out at 80 mph. The drop passed through the supports of another coaster in the same valley: the Thunderbolt. Phantom was reworked a few years ago to remove the inversions and make it a hypercoaster: The Phantom’s Revenge. Phantom (green track) and the T-bolt (white track) are at the northwest end of the park. Notice the shadows for the Phantom’s supports. At the other end of the park, the brownish-red track is the Racer, one of only a handful of “Moebius” racing coasters in the world. Leave the station in the car on the left, return to the station in the car on the right. Just south of it is the Jack Rabbit, featuring a double-dip. The track levels out halfway down the longest hill, providing tremendous airtime.

Our picture is of the Phantom, which looks very cool. Thanks Scott