NASA
Nasa: From Stargazers to Starships: The Round Earth and Christopher Columbus
Despite popular myth, people of the 15th century actually realized that the earth was round. Some scientists had even estimated the size of the Earth. Here's an interesting explanation from a section of an online textbook on the...
Other
Museum of Unnatural History: Hanging Gardens of Babylon
A detailed article on the construction of the Hanging Gardens of Babylon can be found here. Why they were built, how the garden received water, and the exact measurements of the garden are among the topics discussed in the article.
Curated OER
Smithsonian Libraries: Scientific Identity: Strabo (63 Bce 25 Ce)
A portrait of Strabo from the Dibner Library of the History of Science and Technology, made available through the Smithsonian Institution's Scientific Identity Collection.