Architects and engineers

#4
Tower of Pisa
።Italy
Architect
°  Bonanno Pisano
Head engineer
° Bonanno Pisano
Constructed
° Construction began on the tower in 1173 and after almost 200 years, it was completed in 1372.
Facts
° Why was the Leaning Tower of Pisa built?
Construction of the Leaning Tower of Pisa began in 1173 as the third and final structure of the city of Pisa's cathedral complex. In particular, it was built to serve as the complex's bell tower.
° how much does it lean every year?
After a stabilization project, begun in 1990, reduced the quirky monument's dangerous lean by a full 15 inches, the tower has straightened itself out by an additional 1.6 inches since 2001. It still oscillates 0.02 inches over the course of each year, though, the latest results revealed.

#3
SAINT BASIL CATHEDRAL
። Russia
Architects
°  Postnik Yakovlev
° Ivan barma
Head engineer
° engineer Michel Virlogeux
Constructed
° Saint Basil's Cathedral was built between 1555 and 1561
Facts
° The Cathedral of Vasily the Blessed, known in English as Saint Basil's Cathedral, is an Orthodox church in Red Square of Moscow, and is one of the most popular cultural symbols of Russia.
° The cost of construction is unknown
° Today the cathedral consists of ten individual chapels. The largest, central one, the Church of the Intercession, is 46 metres (151 ft) tall internally but has a floor area of only 64 square metres (690 sq ft). 

#2
THE MILLAU VIADUCT
። France
Architect
°  Sir Norman Foster
Head engineer
° engineer Michel Virlogeux
Constructed
° Construction began on 16th of October 2001 and finished in November 2003 but
Opened officially on 16 December 2004, at 9:00
Facts
° across the gorge valley of the Tarn near (west of) Millau in the Aveyron department in the Occitanie Region, in Southern France.
° The cost of construction was approximately €394 million (US$424 million). 
° it is the tallest bridge in the world, at 336.4 metres (1,104 ft) tall.
Design Multiple-span cable-stayed viaduct motorway bridge
Material Concrete, steel
Total length 2,460 m (8,070 ft)
Width 32.05 m (105.2 ft)
Height 336.4 m (1,104 ft) (max pylon above ground) Longest span 342 m (1,122 ft)
Clearance below 270 m (890 ft)
Design life 120 years

#1
THE HOOVER DAM
Architects
° Gordon Kaufmann
° Henry J. Kaiser
Head engineer
° Francis Trenholm Crowe
Constructed
° between 1931 and 1936, during the Great Depression .
Facts
° The dam is located on the border between Nevada and Arizona.
° The dam cost $49 million to build.
° Hoover Dam is 726 feet (221 metres) high and 1,244 feet (379 metres) long at the crest. It contains 4,400,000 cubic yards (3,360,000 cubic metres) of concrete. Four reinforced-concrete intake towers located above the dam divert water from the reservoir into huge steel pipes called penstocks. The water, after falling some 500 feet (150 metres) through the pipes to a hydroelectric power plant in the base of the dam, turns 17 Francis-type vertical hydraulic turbines, which rotate a series of electric generators that have a total power capacity of 2,080 megawatts.