You can spot the opal necklace —which plays a major role years later in The Half-Blood Prince —inside a display case in Borgin and Burkes when Harry first accidentally enters Knockturn Alley.
Rupert Grint (Ron Weasley) has a severe, real-life fear of spiders. In the scene with Aragog, his terrified expressions and squirming weren't acting—he was genuinely frightened and still hasn't watched the full scene.
Released in 2002, Harry Potter and the Chamber of Secrets remains a pivotal entry in the series for its darker tone and introduction of key lore. Beyond the plot, the production was filled with fascinating "movie magic" moments and coincidences.