That's Stonehenge from Ace Combat 04. Adding tags.
--Edit: check the tag "ストーンヘンジ" in the Pixiv page.

Akula said:
That's Stonehenge from Ace Combat 04. Adding tags.
--Edit: check the tag "ストーンヘンジ" in the Pixiv page.

It's an user-added tag.

Looking back, the railgun depicted is definitely not Stonehenge, as its intricacies are vastly different from the one depicted in Strangereal, but I'm going to keep it here since it's largely based on the same structure, and it's not like we can compare the original tags now, with the bad pixiv id tag warning us there is nothing on that other side.