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.
The Eiffel tower in Paris was built for an Exhibition in celebration of the French Revolution. Construction began earnestly in 1884 and about 2 years and 7,000+ tons of iron later it was finished. It was purely decorative for the first 20 years. Then it became the most famous broadcasting mast in the world.