In landscape design terminology, "focal points" force the viewer’s perspective to a particular location. The use of symmetry or balance creates the effect in a more obvious manner, while asymmetrical designs soften or even avoid focalization. As this photo showing a focal point illustrates, focalization is achieved most easily by placing an attractive garden accent on an uncluttered lawn -- there's nothing to compete with the selected ornament for attention.
With the movement and sound they provide, garden fountains (picture at right) make for excellent focal points, capturing one's attention on a number of levels. I supply other examples of the concept in my photo gallery dealing with focal points and other visual cues in landscape design.