King Frederik led royal solar eclipse watchers as he visited an observatory on Wednesday.
The Danish King, 58, marked the end of his summer holiday with Queen Mary as he paid a trip to the Round Tower People's Observatory in Copenhagen, which is Europe's oldest functioning observatory building, built in 1642.
Frederik had the opportunity to observe the sky and even watch the magnificent solar eclipse, grinning as he had a go with the special cardboard glasses.
His visit was to reopen the observatory, as the dome and telescope have undergone extensive renovations over the past six months.
And it managed to coincide with the most incredible solar eclipse view in the sky!
In the UK, more than 90% of the sun was obscured by the Moon between about 6pm and 8.15pm on Wednesday, the most it has been blocked above skies since the total eclipse in 1999.
Spain saw a rare total solar eclipse, although King Felipe and Queen Letizia are currently in Mallorca for their summer holiday.
King Charles is currently in Scotland, meaning that he may have passed up an opportunity to get the very best view of the eclipse.
However, the Princess of Wales's brother, James Middleton, enjoyed watching the spectacle with his family, sharing an adorable picture of son Inigo, two, pointing up at the sky.
Frederik was sadly unaccompanied by his wife, Queen Mary, on this occasion as she was returning home from the World Equestrian Championships in Aachen, where she met Princess Amalia of the Netherlands and Infanta Elena.
The visits mark the Danish royals' return to the official agenda after the summer holidays, with Frederik set to resume his regular audiences on Monday, 17 August.
As is tradition, the couple boarded the Royal Yacht Dannebrog for their annual summer cruise on 6 May. It concluded with a visit to the Holbæk Municipality on June 4.
