Greening introduction: Bonn is one of the greenest cities in Europe. Visitors can see lush trees and colorful flowers and plants everywhere when walking around the city. The city has more than 1,200 large and small parks and street parks. The urban area is surrounded by large forests, covering an area of ​​more than 40 million square meters. Viewed from an airplane, the city is surrounded by a sea of ​​green.