A long exposure shows the illuminated airport behind the city of Zurich and Lake Zurich, Switzerland July 10, 2020. REUTERS/Arnd Wiegmann

A general view shows the castle Stiftung Berliner Schloss-Humboldt Forum with the new dome cross atop in Berlin, Germany June 2, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Stiftung Berliner Schloss-Humboldt Forum with the new dome cross atop in Berlin, Germany June 2, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Stiftung Berliner Schloss-Humboldt Forum with the new dome cross atop in Berlin, Germany June 2, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Stiftung Berliner Schloss-Humboldt Forum with the new dome cross atop in Berlin, Germany June 2, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum, next to the TV tower in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

A general view shows the castle Berliner Schloss - Humboldtforum, next to the TV tower in Berlin, Germany, May 14, 2020. REUTERS/Fabrizio Bensch

The dome is pictured in the old city centre of Wetzlar , Germany, January 16, 2020. Picture taken January 16, 2020. REUTERS/Fabrizio Bensch

Half-timbered houses are seen in the old city centre of Wetzlar, Germany, January 16, 2020. Picture taken January 16, 2020. REUTERS/Fabrizio Bensch

Half-timbered houses are seen in the old city centre of Wetzlar, Germany, January 16, 2020. Picture taken January 16, 2020. REUTERS/Fabrizio Bensch

The Limburg cathedral is pictured in Limburg, Germany, January 16, 2020. Picture taken January 16, 2020. REUTERS/Fabrizio Bensch

The city sign is pictured in Wetzlar, Germany, January 16, 2020. Picture taken January 16, 2020. REUTERS/Fabrizio Bensch

A metro passes by a residential apartment building near the Eiffel Tower in Paris, France, October 18, 2019. REUTERS/Charles Platiau

A residential apartment building is seen near the Eiffel Tower in Paris, France, October 18, 2019. REUTERS/Charles Platiau

A residential apartment building is seen near the Eiffel Tower in Paris, France, October 18, 2019. REUTERS/Charles Platiau

A general views shows the Christmas market, the Bikini Berlin building and the Memorial Church in Berlin, Germany, December 17, 2018. REUTERS/Fabrizio Bensch

General view from the rooftop of the Arche de la Defense which reopens to the public after 7 years of reconstruction in the financial and business district of La Defense at Puteaux, west of Paris, France, June 1, 2017. REUTERS/Charles Platiau

General view from the rooftop of the Arche de la Defense which reopens to the public after 7 years of reconstruction in the financial and business district of La Defense at Puteaux, west of Paris, France, June 1, 2017. REUTERS/Charles Platiau

General view from the rooftop of the Arche de la Defense which reopens to the public after 7 years of reconstruction in the financial and business district of La Defense at Puteaux, west of Paris, France, June 1, 2017. REUTERS/Charles Platiau

A general view shows rooftops with chimney stacks on the rooftops of residential apartment buildings in Paris, France, August 26, 2016. REUTERS/Regis Duvignau

A general view shows rooftops with chimney stacks on the rooftops of residential apartment buildings in Paris, France, August 26, 2016. REUTERS/Regis Duvignau

A cityview shows the Paris skyline from the colonnade of the Pantheon Dome after its restauration in Paris, France, March 30, 2016. REUTERS/Benoit Tessier

A cityview shows the Paris skyline from the colonnade of the Pantheon Dome after its restauration in Paris, France, March 30, 2016. REUTERS/Benoit Tessier

A cityview shows the Paris skyline from the colonnade of the Pantheon Dome after its restauration in Paris, France, March 30, 2016. REUTERS/Benoit Tessier

A cityview shows the Paris skyline from the colonnade of the Pantheon Dome after its restauration in Paris, France, March 30, 2016. REUTERS/Benoit Tessier

A cityview shows the Paris skyline with monuments and roof tops from the colonnade of the Pantheon Dome after its restauration in Paris, France, March 30, 2016. REUTERS/Benoit Tessier

A traditional frame-work house is pictured in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The logo of US motorbike manufacturer Harley Davidson is seen on a "Heritage Softtail" in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A brass plate amid cobble stones commemorate the victims of the WW2 airstrikes against the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A brass plate amid cobble stones shows the ground plan of the ancient Roman city of "Confluentes" at the confluence of the rivers Moselle and Rhine in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A brass plate amid cobble stones commemorate the victims of the WW2 airstrikes against the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The logo of US motorbike manufacturer Harley Davidson is seen on a "Heritage Softtail" in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A traditional frame-work house is pictured in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The logo of US motorbike manufacturer Harley Davidson is seen on a "Heritage Softtail" in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

Sparks against doves are placed on the logo of German telecommunications giant Deutsche Telekom AG at a Telekom mobile phones store in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The emblem of the western German city of Koblenz, a young boy with the nickname "Schaengel" is seen on a manhole cover in the city centre of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The coat of arms of Rhineland-Palatinate (Rheinland Pfalz) is seen at the regional administrative centre of the northern Rhineland-Palatinate formerly know as Bezirksregierung in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A cast iron plate shows the equestrian statue of former German Emperor William I stands at the German Corner (Deutsches Eck) next to the confluence of the river Moselle and Rhine in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A cast iron plate shows the names of the former German regions of Brandenburg, Pommerania, Mecklenburg and East Prussia is seen at the monument of the German Corner (Deutsches Eck) at the confluence of the rivers Moselle and Rhine in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The confluence of the rivers Moselle and Rhine are seen at the German Corner (Deutsches Eck) in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A cast iron plate shows the names of the former German regions of Thuringia, Saxony, Saar and Silesia is seen at the monument of the German Corner (Deutsches Eck) at the confluence of the rivers Moselle and Rhine in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The replica of the giant equestrian statue of former German Emperor William I stands atop of the German Corner (Deutsches Eck) at the confluence of the river Moselle and Rhine in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The confluence of the rivers Moselle and Rhine are seen at the German Corner (Deutsches Eck) in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The statue of German physiologist Johannes Mueller is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A cast iron plate shows the equestrian statue of former German Emperor William I stands at the German Corner (Deutsches Eck) next to the confluence of the river Moselle and Rhine in the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The Florins church is seen next to the official emblem of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

Windows are seen amid of a slate-roof in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

Windows are seen amid of a slate-roof in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

The statue of German physiologist Johannes Mueller is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A BMW i-3 electrical car is refuelled at a power station for e-cars in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A BMW i-3 electrical car is refuelled at a power station for e-cars in the city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A fuel station for e-bikes is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

A fuel station for e-bikes is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

An ecolocial re-fuelling power station for e-cars is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay

An ecolocial re-fuelling power station for e-cars is pictured in the historic city centre of the western German city of Koblenz, March 1, 2016. REUTERS/Wolfgang Rattay