What different kinds of “desert places” are the most important and most frightening?Desert Places by "Robert Frost"

In approaching the analysis of poem, the most important
step is in identifying the controlling metaphor.  This metaphor is the deadness and
spiritlessness of the world that is covered with snow in the dying winter as it compares
to the desolation and isolation of the speaker.

Unlike the
Romatic poets, the speaker's concept of being included in the natural scene is not
uplifting; instead, it is a condition of negativity, just as the man-made field that has
been cultivated for a crop and has the stubble poking through the snow exists negatively
with the rest of the snow-covered scene.

The last stanza,
of course, expresses the most frightening "desert place" as it is the intensity of
nothingness that exists in the soul of the speaker, a place of utter despair in
which the emptiness of the natural scene intensifies his feeling of
nothingness.