Great Wall of China

Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials,for protect the Chinese states and empires against the Raids and invasions of the various nomadic groups . Several walls were being built as early as the 7th century BC; These, later joined together and made bigger and stronger, are now collectively referred to as the Great Wall. Since then, the Great Wall has been rebuilt, maintained, and enhanced; The majority of the wall is from the Ming Dynasty (1368-1644). Great Wall of China is a barrier fortification in northern China running west-to-east 13,171 miles (21,196 km) from the Jiayuguan Pass (in the west) to the Hushan Mountains in Liaoning Province in the east, ending at the Bohai Gulf. It crosses eleven provinces Inner Mongolia and Ningxia. The Great Wall in the present day is almost completely the work of the Ming Dynasty (1368-1664 CE) who added the distinctive watchtowers and expanded the length and width of the wall. The now-famous national monument fell into decay following the Ming Dynasty, when the Qing Dynasty (1644-1912 CE) took power and expanded the border of China northwards, making the wall obsolete. Restoration and preservation efforts only seriously began in the 1980's CE, and the wall was declared a UNESCO World Heritage Site in 1987 CE. Construction of the wall began in the Qin Dynasty (221-206 BCE) under the First Emperor Shi Huangti and continued over hundreds of years throughout many different dynasties.

Other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or regulation of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor .

Great Wall of China stretches from Dandong in the east to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,850 km (5,500 mi). This is made up of 6,259 km (3,889 mi) sections of actual wall, 359 km (223 mi) of trenches and 2,232 km (1,387 mi) of natural defensive barriers such as hills and rivers. Another archaeological survey found that the entire wall with all its branches measures out to be 21,196 km (13,171 mi).

Rome Colosseum

Rome Colosseum is It a large outdoor stadium located in the heart of Rome. A circle of brick and sandstone measures around 527 meters high 57 meters can contain between 50,000 and 80,000 spectators. Intelligently designed by creating an elliptical stadium. To make the audience feel closer to the athlete. And drainage design to avoid flooding in the field during rain. Holds the prototype of the current stadium. It takes about 10 years to build.

Rome Colosseum a major tourist attraction in Rome with thousands of tourists each year paying to view the interior arena, though entrance for citizens of the European Union (EU) is partially subsidised, and entrance is free for EU citizens under eighteen or over sixty-five years of age. There is now a museum dedicated to Eros located in the upper floor of the outer wall of the building. Part of the arena floor has been re-floored. Beneath the Colosseum, a network of subterranean passageways once used to transport wild animals and gladiators to the arena opened to the public in summer 2010.

Rome Colosseum is also the site of Roman Catholic ceremonies in the 20th and 21st centuries. For instance, Pope Benedict XVI led the Stations of the Cross called the Scriptural Way of the Cross (which calls for more meditation) at the Colosseum on Good Fridays.

Rome Colosseum and its activities supported a substantial industry in the area. In addition to the amphitheatre itself, many other buildings nearby were linked to the games. Immediately to the east is the remains of the Ludus Magnus, a training school for gladiators. This was connected to the Colosseum by an underground passage, to allow easy access for the gladiators. The Ludus Magnus had its own miniature training arena, which was itself a popular attraction for Roman spectators. Other training schools were in the same area, including the Ludus Matutinus (Morning School), where fighters of animals were trained, plus the Dacian and Gallic Schools.

Pisa Tower

Pisa Tower (Italian: Torre pendente di Pisa) or simply the Tower of Pisa  is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its unintended tilt. It is situated behind Pisa's cathedral and is the third oldest structure in the city's Cathedral Square, after the cathedral and the Pisa Baptistry. The tower's tilt began during construction, caused by an inadequate foundation on ground too soft on one side to properly support the structure's weight. The tilt increased in the decades before the structure was completed and gradually increased until the structure was stabilized (and the tilt partially corrected) by efforts in the late 20th and early 21st centuries. The height of the tower is 55.86 m (183.27 feet) from the ground on the low side and 56.67 m (185.93 feet) on the high side. The width of the walls at the base is 2.44 m (8 ft 0.06 in). Its weight is estimated at 14,500 MT . The bottom story consists of 15 marble arches. Each of the next six stories contains 30 arches that surround the tower.The final story is the bell chamber itself, which has 16 arches. There is a 297 step spiral staircase inside the tower leading to the top. Prior to restoration work performed between 1990 and 2001, the tower leaned at an angle of 5.5 degrees, but the tower now leans at about 3.99 degrees. This means the top of the tower is displaced horizontally 3.9 m (12 ft 10 in) from the centre.

Manufacture

Pisa Tower occurred in three stages over 199 years. Work on the ground floor of the white marble campanile began on August 14, 1173 during a period of military success and prosperity. This ground floor is a blind arcade articulated by engaged columns with classical Corinthian capitals. The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-metre foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, because the Republic of Pisa was almost continually engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled. In 1198, clocks were temporarily installed on the third floor of the unfinished construction. In 1272, construction resumed under Giovanni di Simone, architect of the Camposanto. In an effort to compensate for the tilt, the engineers built upper floors with one side taller than the other. Because of this, the tower is curved. Construction was halted again in 1284 when the Pisans were defeated by the Genoans in the Battle of Meloria. The seventh floor was completed in 1319. The bell-chamber was finally added in 1372. It was built by Tommaso di Andrea Pisano, who succeeded in harmonizing the Gothic elements of the bell-chamber with the Romanesque style of the tower. There are seven bells, one for each note of the musical major scale. The largest one was installed in 1655. After a phase (1990–2001) of structural strengthening, the tower is currently undergoing gradual surface restoration, in order to repair visible damage, mostly corrosion and blackening. These are particularly pronounced due to the tower's age and its exposure to wind and rain.