Milan Cathedral - 579 Years (1386 - 1965)
The one that took the longest to build :D
Cathedral
The pyramid that took the longest to build was the Great Pyramid. It is believed it took 20 years to build and it is the oldest of the pyramids in Egypt.
The Chartes Cathedral
Let us assume you mean Notre Dame de Paris, and not one of the hundreds of other churches dedicated to Our Lady. In which case, the usual building dates given are 1172 to 1340. But, of course, a Cathedral is never really finished; by the time you have completed the plan, the first bits are 200 years old and need replacing, and so on.
the great wall of china
The longest took about 22 years, for proof I got that off a history book.
The bridge that took the longest to build was the Qingado Haiwan Bridge. This bridge is located in the country of China. It is twenty six point four miles in length.
It took several years to build but was completed about 1700
in 1675 and was completed in 1708- 42 years after the Great Fire of Londonit is 468 yeas old
it took about 20-30 years