Blooming tulips are seen in Gulhane Park, Istanbul, Turkey, on April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

People visit the Gulhane Park in Istanbul, Turkey, April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

Photo taken on April 22, 2019 shows tulips in the Gulhane Park in Istanbul, Turkey. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

People visit the Gulhane Park in Istanbul, Turkey, April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

People visit the Gulhane Park in Istanbul, Turkey, April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

People visit the Gulhane Park in Istanbul, Turkey, April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

People visit the Gulhane Park in Istanbul, Turkey, April 22, 2019. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)

Photo taken on April 22, 2019 shows the Bosphorus Strait seen from the Gulhane Park. Gulhane Park was first built as the outer garden of the imperial Topkapi Palace located at the center of Istanbul. As one of the most ancient city parks in Istanbul, it was opened to the public in 1912. (Xinhua/Xu Suhui)