Sydney Harbour Bridge: Sydney

The Sydney Harbour Bridge is a steel arch bridge across Sydney Harbour that carries rail, vehicular and pedestrian traffic between the Sydney central business district and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic image of both Sydney and Australia. The bridge is locally nicknamed "The Coathanger" because of its arch-based design.

The bridge was designed and built by Dorman Long and Co Ltd, Middlesbrough Teesside and Cleveland Bridge, Darlington, County Durham and opened in 1932. Until 1967 it was the city's tallest structure. According to Guinness World Records, it is the world's widest long-span bridge and it is tallest steel arch bridge, measuring 134 metres (429.6 ft) from top to water level. It is also the fifth-longest spanning-arch bridge in the world.

The southern (CBD) bridge end is located at Millers Point in The Rocks area, and the northern end at Milsons Point in the lower North Shore area. It carries six lanes of road traffic on its main roadway, two lanes of road traffic (formerly two tram tracks) and a footpath on its eastern side, and two railway tracks and a bicycle path along its western side, being 305 mm (1 ft) larger than the east side.

The main roadway across the bridge is known as Bradfield Highway, Sydney, and is about 2.4 km (1.5 miles) long, making it one of the shortest highways in Australia. (The shortest, also called the Bradfield Highway, is found on the Story Bridge in Brisbane).

The Sydney Harbour Bridge is not completely stationary. It can rise or fall up to 18 cm depending on whether it is hot or cold due to the steel expanding or contracting

Tsing Ma Bridge: Hong Kong

The Tsing Ma Bridge is a bridge in Hong Kong. It is the world's seventh-longest span suspension bridge. The bridge was named after two of the islands at its ends, namely Tsing Yi and Ma Wan . It has two decks and carries both road and rail traffic, which also makes it the largest suspension bridge of this type. The bridge has a main span of 1,377 metres (4,518 ft) and a height of 206 metres (676 ft). The span is the largest of all bridges in the world carrying rail traffic.

The 41 metres (135 ft) wide bridge deck carries six lanes of automobile traffic, with three lanes in each direction. The lower level contains two rail tracks. There are also two sheltered carriageways on the lower deck for maintenance access and as backup for traffic when particularly severe typhoons strike Hong Kong. Though road traffic would need to be closed in that case, trains could still get through in either direction.

Oresund Bridge: Öresund strait

The Øresund or Öresund Bridge is a combined two-track rail and four-lane road bridge-tunnel across the Öresund strait. It is the longest combined road and rail bridge in Europe and connects the two metropolitan areas of the Öresund Region: the Danish capital of Copenhagen and the Swedish city of Malmö. The international European route E20 runs across the bridge and through the tunnel via the two lane motorway, as does the Öresund Railway Line. The bridge is the longest border crossing bridge in the world, but due to the Schengen Agreement, there are no passport controls. However there are frequent random customs control checks at the toll booths on the Swedish side for those entering Sweden, but not when entering Denmark.

The bridge has one of the longest cable-stayed main spans in the world at 490 metres (1,608 ft). The height of the highest pillar is 204 metres (669 ft). The total length of the bridge is 7,845 metres (25,738 ft), which is approximately half the distance between the Swedish and Danish landmasses, and its weight is 82,000 tonnes. The border is located 2.5 km (1.6 mi) from the western end and 5.3 km (3.3 mi) from the eastern end of the bridge. On the bridge, the two rail-tracks are beneath the four road lanes. The bridge has a vertical clearance of 57 metres (187 ft), although most boat traffic across Oresund still passes over the Drogden strait (where the tunnel lies). The bridge's architecture is by Georg Rotne, with structural design made by Arup.

Tower Bridge: London, England

Tower Bridge is a combined bascule and suspension bridge in London, England, over the River Thames. It is close to the Tower of London, which gives it its name. It has become an iconic symbol of London. Tower Bridge is one of several London bridges owned and maintained by the City Bridge Trust, a charitable trust overseen by the City of London Corporation.

The bridge consists of two towers which are tied together at the upper level by means of two horizontal walkways which are designed to withstand the horizontal forces exerted by the suspended sections of the bridge on the land-ward sides of the towers. The vertical component of the forces in the suspended sections and the vertical reactions of the two walkways are carried by the two robust towers. The bascule pivots and operating machinery are housed in the base of each tower. Its present colour dates from 1977 when it was painted red, white and blue for the Queen's Silver Jubilee. Originally it was painted a chocolate brown colour.

Tower Bridge is sometimes mistakenly referred to as London Bridge, which is actually the next bridge upstream. A popular urban legend is that in 1968, Robert McCulloch, the purchaser of the old London Bridge that was later shipped to Lake Havasu City, Arizona, believed that he was in fact buying Tower Bridge. This was denied by McCulloch himself and has been debunked by Ivan Luckin, the seller of the bridge.

Golden Gate Bridge: San Francisco, USA

The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay onto the Pacific Ocean. As part of both U.S. Route 101 and California State Route 1, it connects the city of San Francisco on the northern tip of the San Francisco Peninsula to Marin County. The Golden Gate Bridge was the longest suspension bridge span in the world when it was completed during the year 1937, and has become an internationally recognized symbol of San Francisco and California. Since its completion, the span length has been surpassed by eight other bridges. It still has the second longest suspension bridge main span in the United States, after the Verrazano-Narrows Bridge in New York City. In 2007, it was ranked fifth on the List of America's Favorite Architecture by the American Institute of Architects.

Strauss was chief engineer in charge of overall design and construction of the bridge project. However, because he had little understanding or experience with cable-suspension designs, responsibility for much of the engineering and architecture fell on other experts.

Irving Morrow, a relatively unknown residential architect, designed the overall shape of the bridge towers, the lighting scheme, and Art Deco elements such as the streetlights, railing, and walkways. The famous International Orange color was originally used as a sealant for the bridge. Many locals persuaded Morrow to paint the bridge in the vibrant orange color instead of the standard silver or gray, and the color has been kept ever since.

Senior engineer Charles Alton Ellis, collaborating remotely with famed bridge designer Leon Moisseiff, was the principal engineer of the project. Moisseiff produced the basic structural design, introducing his "deflection theory" by which a thin, flexible roadway would flex in the wind, greatly reducing stress by transmitting forces via suspension cables to the bridge towers. Although the Golden Gate Bridge design has proved sound, a later Moisseiff design, the original Tacoma Narrows Bridge, collapsed in a strong windstorm soon after it was completed, because of an unexpected aeroelastic flutter.

With an eye toward self-promotion and posterity, Strauss downplayed the contributions of his collaborators who, despite receiving little recognition or compensation, are largely responsible for the final form of the bridge. He succeeded in having himself credited as the person most responsible for the design and vision of the bridge. Only much later were the contributions of the others on the design team properly appreciated. In May 2007, the Golden Gate Bridge district issued a formal report on 70 years of stewardship of the famous bridge and decided to right an old wrong by giving Ellis major credit for the design of the bridge.

Ponte Vecchio: Florence, Italy

The Ponte Vecchio is a Medieval bridge over the Arno River, in Florence, Italy, noted for still having shops built along it, as was once common. Butchers initially occupied the shops; the present tenants are jewelers, art dealers and souvenir sellers. It has been described as Europe's oldest wholly-stone, closed-spandrel segmental arch bridge, but there are far older segmental arch bridges such as Alconétar Bridge. The Ponte Vecchio's two neighbouring bridges are the Ponte Santa Trinità and the Ponte alle Grazie.

Kintaikyo: Iwakuni, Japan

Possibly one of the most unlucky bridges in the world, Kintaikyo was reconstructed in the town of Iwakuni in 1673 after every other attempt to cross the Nishiki River via bridge had been foiled by seasonal flooding. Remarkably, the five wooden arches remained intact right up to 1950 when a typhoon finally destroyed them. However, intent on not being beaten, the bridge was again reconstructed three years later and is still crossable today