World heritage monuments

We live in a wonderful world constructed by God and maintained by life forms. There are a hand full of monuments designed and constructed by humans of different ages. Here is a small list of heritage structures from around the globe.

The Eiffel Tower in Paris – a symbol of France:

  Is an iron lattice tower located on the Champ de Mars in Paris. It was named after the engineer Gustave Eiffel, whose company designed and built the tower. Erected in 1889 as the entrance arch to the 1889 World's Fair, it was initially criticised by some of France's leading artists and intellectuals for its design, but has become both a global cultural icon of France and one of the most recognizable structures in the world^. The tower is the tallest structure in Paris and the most-visited paid monument in the world; 6.98 million people ascended it in 2011. The tower received its 250 millionth visitor in 2010^.
The tower is 324 metres (1,063 ft) tall, about the same height as an 81-storey building. During its construction, the Eiffel Tower surpassed the Washington Monument to assume the title of the tallest man-made structure in the world, a title it held for 41 years, until the Chrysler Building in New York City was built in 1930. Because of the addition of the antenna atop the Eiffel Tower in 1957, it is now taller than the Chrysler Building by 5.2 metres (17 ft). Not including broadcast antennae, it is the second-tallest structure in France, after the Millau Viaduct.
The tower has three levels for visitors, with restaurants on the first and second. The third level observatory's upper platform is 276 m (906 ft) above the ground, the highest accessible to the public in the European Union. Tickets can be purchased to ascend by stairs or lift (elevator) to the first and second levels. The climb from ground level to the first level is over 300 steps, as is the walk from the first to the second level. Although there are stairs to the third and highest level, these are usually closed to the public and it is generally only accessible by lift.

Material

The puddled iron (wrought iron) structure of the Eiffel Tower weighs 7,300 tonnes, while the entire structure, including non-metal components, is approximately 10,000 tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of the metal structure were melted down it would fill the 125-metre-square base to a depth of only 6.25 cm (2.5 in), assuming the density of the metal to be 7.8 tonnes per cubic metre.Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7.1 in) because of thermal expansion of the metal on the side facing the sun.

Wind considerations

At the time the tower was built many people were shocked by its daring shape. Eiffel was accused of trying to create something artistic without regard to engineering. However, Eiffel and his engineers, as experienced bridge builders, understood the importance of wind forces and knew that if they were going to build the tallest structure in the world they had to be certain it would withstand them. In an interview with the newspaper Le Temps (Paris) of 14 February 1887, Eiffel said

Now to what phenomenon did I give primary concern in designing the Tower? It was wind resistance. Well then! I hold that the curvature of the monument's four outer edges, which is as mathematical calculation dictated it should be … will give a great impression of strength and beauty, for it will reveal to the eyes of the observer the boldness of the design as a whole.

 

 

The Colosseum in Rome, known worldwide:

 The Colosseum or Coliseum, also known as the Flavian Amphitheatre (Latin: Amphitheatrum Flavium; Italian: Anfiteatro Flavio or Colosseo) is an elliptical amphitheatre in the centre of the city of Rome, Italy. Built of concrete and stone, it was the largest amphitheatre of the Roman Empire, and is considered one of the greatest works of Roman architecture and engineering. It is the largest amphitheatre in the world.

Exterior

Original façade of the Colosseum

Unlike earlier Greek theatres that were built into hillsides, the Colosseum is an entirely free-standing structure. It derives its basic exterior and interior architecture from that of two Roman theatres back to back. It is elliptical in plan and is 189 meters (615 ft / 640 Roman feet) long, and 156 meters (510 ft / 528 Roman feet) wide, with a base area of 6 acres (24,000 m²). The height of the outer wall is 48 meters (157 ft / 165 Roman feet). The perimeter originally measured 545 meters (1,788 ft / 1,835 Roman feet). The central arena is an oval 87 m (287 ft) long and 55 m (180 ft) wide, surrounded by a wall 5 m (15 ft) high, above which rose tiers of seating.

Interior seating

The raked areas that once held seating

According to the Codex-Calendar of 354, the Colosseum could accommodate 87,000 people, although modern estimates put the figure at around 50,000. They were seated in a tiered arrangement that reflected the rigidly stratified nature of Roman society. Special boxes were provided at the north and south ends respectively for the Emperor and the Vestal Virgins, providing the best views of the arena. Flanking them at the same level was a broad platform or podium for the senatorial class, who were allowed to bring their own chairs. The names of some 5th century senators can still be seen carved into the stonework, presumably reserving areas for their use.


The Big Ben

Saint Basil’s Cathedral, Moscow, Russia

Leaning Tower of Pisa, Pisa, Italy

London Tower Bridge

Taj Mahal

Bahai Temole