[staplung]

That's okay, even Stonehenge isn't a proper henge. For official henge status you need to have a ditch inside a raised bank. At Stonehenge, it's the opposite; the ditch is outside the bank. When I visited there a few years ago with some friends I took to calling it Stonething.

[technothrasher]

To be fair though, the modern word ‘henge’ meaning a circular embankment with an internal ditch, was derived from the name of Stonehenge. So that while Stonehenge is not a henge monument, one cannot fairly complain that it is named incorrectly. If anything, its the term 'henge' which has been incongruously repurposed.