Three short lines give us a single scene: a speaker standing beside an oak that has a huge, round hole in it. Nothing happens. No one speaks, and the poem doesn't tell us how the hole got there. What it gives us instead is the silence, which the speaker calls "uncanny."
That word does most of the work. Uncanny means strange in a way that makes you uneasy, as if something familiar has turned slightly wrong. A tree is usually full of small sounds, like leaves, insects and birds, so the quiet feels unnatural, almost like the tree is holding its breath. The hole becomes a kind of open mouth or empty eye, and it draws the attention without explaining itself.
The speaker seems unsettled but also fascinated, someone who stops and listens rather than hurrying past. The mood is hushed, a little eerie, and very still. The poem leaves you standing in that stillness, wondering what the hole means.