The power of context...

... can be seen in a simple weekend exercise: look up your favourite area on your handy 3D online maps, and you just might get a slew of features, some of it unwanted...

On a recent walk near where I live in Cambridgeshire, I stumbled across this feature on Iram Drove, Willingham: it's an Iron Age settlement or a medieval fort, bisected by a recent path.

Bing Maps Birdseye view shows this best. Although the vintage of the satellite imagery or aerial shots is unknown, the fort ring as well as ridge-and-furrow show well.

Hint: rotate clockwise and anticlockwise to see it better
(if you rotate twice and revert to map mode,
refresh the browser to return to the birds-eye view).

click on image to access web

ArcGIS Explorer Online's map, without adding basemaps in this area, shows in shadow relief a circle next to the pushpin.

click on image and then search for:
iram drove, willingham, cambridgeshire

Search for the same on Google Maps and you'll find a 'teapot spout' on the eastern edge - that is simply a drainage ditch to empty what remains of the moat, in this water-logged region.

click on image and then search for:
iram drove, willingham, cambridgeshire

Note however the a-contextual search Google did: it posted an unrelated link, because the word iram has many, many meanings.