Tower of Pisa -- Pisa, Italy

The Tower of Pisa is the bell tower of the Cathedral. Its construction began in the august of 1173 and continued (with two long interruptions) for about two hundred years, in full fidelity to the original project, whose architect is still uncertain.
In the past it was widely believed that the inclination of the Tower was part of the project ever since its beginning, but now we know that it is not so. The Tower was designed to be "vertical" (and even if it did not lean it would still be one of the most remarkable bell towers in Europe), and started to incline during its construction.
Both because of its inclination, and its beauty, from 1173 up to the present the Tower has been the object of very special attention. During its construction efforts were made to halt the incipient inclination through the use of special construction devices; later colums and other damaged parts were substituted in more than one occasion; today, interventions are being carried out within the sub-soil in order to significantly reduce the inclination and to make sure that Tower will have a long life.
In all this story it is possible to find a meaningful constant, the "genetic code" of the Tower: its continual interaction with the soil on which it was built. Today's (1999) works for the safeguard and the conservation of the Tower with very advanced methodologies are designed to fully respect this constant.

Eiffel Tower -- Paris, France

The Eiffel Tower was built for the International Exhibition of Paris of 1889 commemorating the centenary of the French Revolution. The Prince of Wales, later King Edward VII of England, opened the tower. Of the 700 proposals submitted in a design competition, Gustave Eiffel's was unanimously chosen. However it was not accepted by all at first, and a petition of 300 names - including those of Maupassant, Emile Zola, Charles Garnier , and Dumas the Younger - protested its construction.

At 300 metres (320.75m including antenna), and 7000 tons, it was the world's tallest building until 1930. Other statistics include:

• 2.5 million rivets.
• 300 steel workers, and 2 years (1887-1889) to construct it.
• Sway of at most 12 cm in high winds.
• Height varies up to 15 cm depending on temperature.
• 15,000 iron pieces (excluding rivets).
• 40 tons of paint.
• 1652 steps to the top.

It was almost torn down in 1909, but was saved because of its antenna - used for telegraphy at that time. Beginning in 1910 it became part of the International Time Service. French radio (since 1918), and French television (since 1957) have also made use of its stature.

During its lifetime, the Eiffel Tower has also witnessed a few strange scenes, including being scaled by a mountaineer in 1954, and parachuted off of in 1984 by two Englishmen. In 1923 a journalist rode a bicycle down from the first level. Some accounts say he rode down the stairs, other accounts suggest the exterior of one of the tower's four legs which slope outward.

However, if its birth was difficult, it is now completely accepted and must be listed as one of the symbols of Paris itself.