Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: From floating spoons and coffins to crabs and pyramids, alien hunters are often reporting strange structures in images beamed back from the surface of Mars. Now, the latest 'discovery' seen using high-resolution images of the Martian surface, a mysterious circle of stones have been spotted on top of a raised mound on the planet. Dubbed 'Marshenge', alien enthusiasts have been comparing it to the famous stone circle at Stonehenge in Wiltshire, England. The strange cluster of stones has already triggered theories that it may have been built by aliens. However, experts have in the past said such stone circles may form as a result of natural processes that also occur here on Earth.Alien hunters claim to have spotted a stone circle on the surface of MarsThey claim it resembles the famous Stonehenge formation in WiltshireHowever, experts have warned that stone circles can also form naturallyIt is the latest in a long line of strange 'objects' spotted in images of Mars 
 Question:Earlier this month archaeologists announced the discovery of another line of standing stones around a mile away from _ that dates back 4,500 years.

Stonehenge