St Rule's Tower in St Andrews, a magnificent viewpoint well worth the climb to the top. The tower was built in about 1123 and predates the start of building work on the nearby (now ruined) St Andrews Cathedral by almost 40 years. More pics and info: https://www.undiscoveredscotland.co.uk/standrews/strules/index.html
A triumph of over-engineering, the Forth Bridge, often called the Forth Rail Bridge since the arrival of the Forth Road Bridge: now one of three great bridges across this part of the Firth of Forth, each built in a different century. More pics and info: https://www.undiscoveredscotland.co.uk/queensferry/forthrailbridge/index.html
Polar stratospheric or nacreous clouds last Christmas.
Due to their altitude of 15,000–25,000 m (49,000–82,000 ft) and the curvature of the Earth's surface, these clouds shine brightly before dawn or after dusk. Consisting of ice crystals, these form below −78°C (−108°F) and are now more common outside of the polar regions due to global warming.
This has to be one of the most impressive sunrises I've ever seen, and I've seen a lot!
Christmas morning 2020, and one of the best gifts that year was this stunning sky. Brief but gorgeous, complete with a sun pillar caused by ice crystals suspended in the cold air.