Complex sentence: Bankplassen was laid out with the city's first bed of flowers in a public park (around 1860), trees were planted around Oslo Cathedral and Trefoldighetskirken and the organisation managed to stop construction at Kontraskjæret.
Split into simpler sentences: Bankplassen was laid out with the city's first bed of flowers in a public park (around 1860). Trees were planted around Oslo Cathedral and Trefoldighetskirken, and the organisation managed to stop construction at Kontraskjæret.