Singer Madonna performs during her concert at the AccorHotels Arena in Paris, France, December 9, 2015, on her Rebel Heart Tour. (Photo by Benoit Tessier/Reuters)

The Jumbo Stay blends into the background at Stockholm Arlanda Airport. If you spot it as your plane rolls along a taxiway, you might notice an aging widebody jet parked by its lonesome self in a secluded part of the airport.

Korean Air flight attendants photograph a therapy dog dressed in a Superman Halloween costume, as part of a program to de-stress passengers at the international boarding gate area of LAX airport in Los Angeles, California, United States, October 27, 2015. (Photo by Lucy Nicholson/Reuters)

View of a light show on the city's iconic Arc de Triomphe monument during the New Year celebration in Paris, France, December 31, 2016. (Photo by Jacky Naegelen/Reuters)

A model presents a creation by Australian designers Tamara Ralph and Michael Russo as part of their Haute Couture Spring/Summer 2017 fashion show for Ralph & Russo in Paris, France January 23, 2017. (Photo by Gonzalo Fuentes/Reuters)

A French farmer leads her cow through the livestock area as preparations continue on the eve of the opening of the International Agricultural Show in Paris, France, February 26, 2016. The Paris Farm Show runs from February 27 to March 6, 2016. (Photo by Benoit Tessier/Reuters)

The Eiffel Tour-the body language of balance. I came across this group of young adults from Sarajevo, Bosnia, having fun testing their balance two nights ago in on the Esplanade de Trocadero. (Photo and comment by Peter Turnley)

A model wears a creation for Stephane Rolland's Spring-Summer 2016 Haute Couture fashion collection presented in Paris, Tuesday, January 26, 2016. (Photo by Francois Mori/AP Photo)