Translation:The parks are historical and interesting.
I really would recommend a translation of "historic" here. "Historical" usually has to do with the study of history, e.g. historical institutes of various countries. "Historic" usually refers to something that has played a significant role in history, e.g. a historic speech, house, date. Many other languages do not make this distinction, but some (Hungarian, Czech, Slovak) do, I think, make something like this.
I suppose you are right, though historic parks (Tivoli Gardens, the Bois de Boulogne, Central Park, Lincoln Park, VDNKh, etc.) are a lot more common than historical parks, which I suppose would be open air historical museums. The Statue Park outside Budapest, in which the Communist era monuments are gathered would be a historical park to me, for instance.