Exploring the deep ocean floor: Hot springs and strange creatures. The ocean floor is home to many unique communities of plants and animals. Most of these marine ecosystems are near the water surface, such as the Great Barrier Reef, a 2,000-km-long coral formation off the northeastern coast of Australia.
Quick Answer. Egyptian pyramids often took 10 years or more to complete. According to the Greek historian Herodotus, the Great Pyramid at Giza was built in 20 years by 100,000 workers and was meant to be a tomb for Pharaoh Khufu.
Quick Answer. The Empire State Building took 410 days to build. Construction began on March 17, 1930, and the opening ceremony took place on May 1, 1931. The pre-construction work of demolishing the existing building and excavating the site took less than two months. Continue Reading.