Complex sentence: The Gothenburg Botanical Garden is one of the leading botanical gardens in Europe, and was planned by the city council, created thanks to generous doners and inaugurated in 1923 when Gothenburg celebrated its 300th anniversary.
Split into simpler sentences: The Gothenburg Botanical Garden is one of the leading botanical gardens in Europe. It was was planned by the city council, created thanks to generous donors, and inaugurated in 1923 when Gothenburg celebrated its 300th anniversary.