We took an afternoon trip to Stonehenge from Bath which is about an hour ride by bus. The bus dropped us off at the visitor center (basically a parking lot in the middle of a field). There is a museum, cafe and gift shop here as well. The museum is quite small. It does have a few interesting artifacts, a fun time-lapse video of the site and outside there are some period dwelling re-creations, like this one.
There are two options to get to the actual Stonehenge site. One is this bus which has the exciting title of "to the stones". You can also walk which appears to be more informative because there is additional signage around the barrows and nearby structures that go with the actual stones. We intended to walk one way and take the bus the other but because we were on a tour, we had limited time and had to bus both ways.
There is an audio tour of the site along with some numbered spots in the middle of a field to stand and listen at. Really everything here is in the middle of a field. An actively farmed field which for some reason surprised me. There is also a line of camper vans nearby. They are mostly here to either view the site without paying entry or to await the return of aliens or something equally supernatural. Sadly, this is not surprising.
There is also a fairly major motorway crossing not far from the stones. It seems to be a permanent traffic issue as cars slow to view the stones. This seems like a major flaw in Wiltshire traffic planning but maybe it's not always as bad as it was during our visit.
Speaking of the stones, there are two different types and they've come from a considerable distance (Wales in one case) to arrive here in this field in Wiltshire. That alone may be a more impressive feat of engineering than the part where they were stood up in place.
Obviously some of the stones have fallen over in the more than 2000 years since the site was first built. Several of the remaining stones have been inconspicuously strengthened with concrete so they don't topple over on unsuspecting visitors. There are several ways to get close enough to touch the stones. That involves a specialized tour before or after normal hours, or alternately you can visit on an equinox or solstice.
Surrounding the stones are a series of burial mounds visible as small conical hills in nearby fields. There are also several ancient roads that converged at Stonehenge. They are best seen in the museum on aerial photos of the region.
We mentioned that the city of Bath addicted our child to audio tours. Here he is unwilling to stop listening long enough to pose for a photo. A leisurely circuit of the monument while listening to all the available information takes around an hour.