Making the world better, one answer at a time. The primary germ layers (endoderm, mesoderm, and ectoderm) are formed and organized in their proper locations during gastrulation. Endoderm, the most internal germ layer, forms the lining of the gut and other internal organs. Ectoderm, the most exterior germ layer, forms skin, brain, the nervous system, and other external tissues. Mesoderm, the the middle germ layer, forms muscle, the skeletal system, and the circulatory system.
Eiffel Tower. The Eiffel Tower, located in Champ de Mars in Paris, is a tall wrought-iron structure made by man. It is one of the most famous monuments of the world. It is the most famous landmark of Europe, held the record as the tallest man-made structure of the world from 1889 to 1930 with its height of 324 meters.
Materials: Wrought iron. Engineer(s): Gustave Eiffel. The Eiffel Tower, built in commemoration of the French Revolution, was the tallest building in the world when it was unveiled at the Paris World's Fair in 1889.