The shelf above a fireplace or the decorative frame surrounding a fireplace opening.
From Old French 'mantel,' variant of 'mantle,' meaning a covering or cloak. The spelling 'mantel' (vs. 'mantle') became standard for the architectural feature in American English.
The mantelpiece became the original 'gallery wall'—Victorian families displayed their most prized possessions, photographs, and trophies there, which is why we still call a fireplace collection one's 'mantels.'
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