A cultural landscape is actually a rather interesting concept. It can be defined as an area associated with an historic event that will typically include land, plants, people, landmarks, etc. and will typically have some kind of cultural significance. A lot of people have been to one at some point in their lives. If one has visited any of the Civil War sites in the United States, they have been to a cultural landmark.
The Church of Latter-Day Saints considers the Susquehanna River to be a cultural landmark; they have a historical marker there. However, it doesn’t always have to be so specific. A family house can be a cultural landscape to that family, as an example of a smaller cultural landscape.