PIZZAQ Answer: The Ring of Brodgar! And Bob's going to see it! And buy the t-shirt!
Okay, well, it wasn't Swiss cows who like to arrange themselves in a circle. But PatfromCH guessed Stone Circle, and that earns him some Pizza credited to his account.
It's the Ring of Brodgar, one of the most magnificent neolithic stone circles on Planet Earth.
The Orkneys are an archipelago of islands off the north coast of Scotland. (You catch the ferry from Bergen or from Aberdeen.)
Just to confuse the crap out of everybody, the biggest island, with the most stuff on it, is called Mainland. Vleeptron will not use that word again, to prevent tourists as clueless as I usually am from trying to find the Ring of Brodgar on the Scottish mainland. Ask instead for the village of Stenness. If you can get to Stenness, you're just a stroll from the Ring of Brodgar, and several other remarkable neolithic sites, which UNESCO has lumped together as a World Heritage Site.
If the aerial photograph looks like an ellipse rather than a circle, the skewed camera angle probably projected the actual circle into this elliptical shape -- in other words, the camera wasn't looking straight down. But several web pages confidently proclaim that the original 60 stones (of which 27 today remain) were indeed placed in a perfect circle.
An ellipse is one of the Conic Sections, Platonic objects of great interest to the classical Greek geometers, and a circle is a special case of an ellipse. In other words, you can make both an ellipse or a circle by slicing an ice-cream cone (right circular cone) with a big razor blade (plane). You can also slice the ice-cream cone to make a parabola or a hyperbola.
There doesn't seem to be much doubt about what it is. It's an astronomical calendar -- an observatory, an orrery, a planetarium -- capable of precisely pointing to a large set of heavenly phenomena -- solstice and equinox sunrises, seasonal shifting of the Zodiac, etc.
Regardless of the specifics of the builders' belief system, they were farmers, and they lived or died on their predictive understanding of the cyclical movements of the Sun. They were grateful to the Sun and obsessively curious about it. In these times, there was no distinction between priests and mathematicians.
Phoenicians mined tin in these regions and may have brought the 60-based (sexigessimal) geometry of the Mesopotamians to the Orkney dwellers, which may have inspired the design of 60 stones.
Near the Ring of Brodgar is a smaller stone circle dedicated to the movements of the Moon. A deep thread of ancient belief systems is that the Sun represents the cosmic male principle and the Moon the female principle. The phases of the Moon and menstruation -- not coincidentally -- are monthly cycles.
All animal life obviously issues from females (the exact nature and function of sperm was not discovered until the late 19th century), and all land plant life depends on the Sun. Animals eat the plants, and some animals eat animals that eat plants. But everything and everybody needs the Sun. It's the kind of thing that makes you and your neighbors want to get hernias hauling 60 huge stones around for a decade or a century.
Please wish me just a bit of luck, and I may indeed see the Ring of Brodgar sometime this summer. I might even set my travel alarm to watch the Sun rise from the center of the Ring of Brodgar. If I want the sunset, notice that it's at the opposite end of the same stright line from center to sunrise. And I'll buy the t-shirt and the refrigerator magnet and the coffee mug and the cloisonee travel pin.