People ride bicycles at the Tiergarten Park in Berlin, capital of Germany, on Oct. 31, 2019. (Photos: Xinhua)

The Berlin Victory Column is seen behind leaves at the Tiergarten Park in Berlin, capital of Germany, on Oct. 31, 2019.

Leaves are seen at the Tiergarten Park in Berlin, capital of Germany, on Oct. 31, 2019.

A boat is seen on a lake at the Tiergarten Park in Berlin, capital of Germany, on Oct. 31, 2019.

A swan is seen by a lake at the Tiergarten Park in Berlin, capital of Germany, on Oct. 31, 2019.

Photo taken on Oct. 31, 2019 shows a view of the Tiergarten Park in Berlin, capital of Germany.