historical-nonfiction:

Welcome to Derinkuyu, an underground city that once housed up to 20,000 people. In the Cappadocia region, famous for its cave dwellings and underground villages, Derinkuyu stands out for sheer size and complexity. Locals began digging in the 500s BCE. The city consists of over 600 doors, each of which can be closed from the inside. Each floor could be closed off as well. And just to make attacking completely impossible, the entire city was deliberately built without any logic. Its maze-like layout makes navigating the city nightmarish for unfamiliar invaders.

(Source: whenonearth.net, via ohlilo)

thedemon-hauntedworld:

NGC 300

Hubble’s Advanced Camera for Surveys shows individual stars, clusters of stars and nebulae in the spiral galaxy NGC 300, located approximately 7 million light-years away from Earth. The image shows a star-forming region a few thousand light-years farther from the galaxy’s centre. The yellow nebulosities are the glow from hot gas that has been heated by radiation from the nearest young, blue stars. The image at far right reveals more diffuse groupings of young, blue stars, farther away from the galaxy’s centre, along with faint shells of hot gas.

Credit: NASA, ESA, J. Dalcanton and B. Williams (University of Washington)

(via n-a-s-a)