"We will visit the history museum on Thursday afternoon."
参观 is to visit a place, usually for information, an overview or as an experience. We can use it on visiting museums, galleries, factories, schools, offices. Usually it is not used on visiting natural sceneries or landscape.
We visited the new production line of our supplier.
观光 is to visit for touristic purpose. It does not carry a direct object.
We visited around in Washington.