Visitors stand in front of a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)

Visitors walk behind a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)

Visitors walk in front of a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)

A cild runs in a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)

Visitors walk in a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)

In this picture taken with a long time exposure visitors walk in a light installation during the festival 'Magic light worlds' (Magische Lichterwelten) at the zoo park in Halle (Saale), Germany, Friday, March 8, 2019. Chinese lantern artist created around 350 different light sculptures and light installations for the zoo. The festival can be seen until Sunday, March 17, 2019. (AP Photo/Jens Meyer)