St Magnus Cathedral, founded in 1137, is breath-taking.
The Ring of Brodgar is, of course, much older, c.4400-4600 years old, and older than Stonehenge.
Skara Brae is a stone-built Neolithic settlement that was probably occupied before the Ring of Brodgar was built. It is on a stunning coastline. Sand buried it for thousands of years and the sand or the sea may eventually reclaim it.
As we were on a Canadian ship with approximately 150 Canadians, we also visited a more unusual site, the Hall of Clestrain, the childhood home of explorer John Rae (1813-1893). He qualified as a medical doctor in Edinburgh and then joined the Hudson Bay Company. He worked for them for many years in Canada and became an explorer and surveyor. In 1854 he found the final link in the first navigable North West Passage and discovered that the Franklin expedition had ended in disaster. His Orkney birth place has been unoccupied (except for pigs and chickens) for decades. The John Rae Society is trying to raise funds to at least safeguard it if not restore it.
We were sad to sail away and long to return.