かがみの海（津屋崎海岸）

This guide to Kagami no Umi, the mirror sea on the Tsuyazaki coast near Fukuoka, opens with a 2021 photograph of a runner caught mid-stride against a perfectly doubled sky, submitted to a local photo contest. It traces the roughly three-kilometer stretch of shoreline and the retreating tide that leaves behind a sheet of water thin enough to hold that reflection. You'll hear why photographers now time entire visits around that narrow window near sunrise and sunset. Watch the sand at your feet as the tide pulls back.