Poe's valley begins like a fairy tale and ends like a funeral. In the opening lines it is a "silent dell" that "smiled", a peaceful place the people have left to go "unto the wars". They trusted the "mild-eyed stars" to "keep watch above the flowers" while they were away. Then comes the italicised "Now", and the mood turns. Visitors will "confess / The sad valley's restlessness." The poem never says what happened to the people. The nameless grave at the end, though, suggests that the watch failed and that the valley has been mourning ever since. That is an inference from the imagery, but the poem is built to invite it.
The central idea is that a place can hold grief the way a person does. The poem rests on a paradox: "Nothing there is motionless", and yet the air itself, which should be doing the moving, only "broods". The trees "palpitate like the chill seas / Around the misty Hebrides", and the clouds "rustle through the unquiet Heaven", yet the speaker insists twice, "by no wind" are they stirred. The repeated "Ah, by no wind" reads like a gasp. The motion is eerie because it has no natural cause. The valley trembles like a nervous body, and the phrase "magic solitude" tells us we are no longer dealing with ordinary weather.
The form helps the unease. The first lines are short, seven-syllable lines that fall on a stressed syllable ("*Once* it smiled a silent dell"), with a neat, nursery-rhyme chime. As the valley turns restless, the rhymes begin to multiply. "Confess", "restlessness" and "motionless" pile up into a triple rhyme, as do "trees", "seas" and "Hebrides", and later "driven", "Heaven" and "even". Where we expect a couplet, a third rhyme arrives, and the verse seems unable to stop, much like the valley. The lines also lengthen slightly to eight syllables, so the rhythm loosens just as the scene becomes more disturbed. Even the sounds do some of the work. "Lazily lay" is slow and sunlit, while "rustle", "unceasingly" and "palpitate" are full of hissing, tapping consonants.
The imagery gets stranger the closer the poem moves to the ground. The violets lie "in myriad types of the human eye", so the flowers become countless eyes. This reverses the opening. The people trusted the stars' "mild eyes" to watch over the flowers, and now the flowers themselves stare back, as if the valley has taken over the watching and the witnessing. The colour also shifts. The "red sun-light" of the opening lines, which could suggest warmth or blood, gives way to the "chill" seas and "misty" distance.
The last four lines work like a small machine. "They wave:—... They weep:—" are each followed by a colon, and the consequence arrives in the next phrase: dew falls "in drops" and tears "descend in gems". Dew is a natural thing, but Poe calls it "eternal", and the tears are "perennial", a word borrowed from gardening that here means they return every year, forever. The "gems" are lovely and sorrowful at once, which sums up the poem's whole manner. Beauty and grief cannot be separated. The grave is "nameless", so the flowers weep for someone the poem will not identify, and that withheld name keeps the mourning from ever being resolved.
The poem is significant because it shows how much mood can do without a plot. There are no characters, no speech and no explanation, only a landscape, and yet it carries a whole story of absence and loss. Poe, an American writer best known for his dark and atmospheric work, makes the setting the sufferer. The valley is the one who remembers, and its restlessness is the memory. By letting the rhymes crowd and the trees tremble without wind, he makes the reader feel the unease before understanding it, and an unexplained sadness can linger longer than a story told in full.