The Barred Island
Tide Window

This one lives and dies by the tide chart. Check it the night before — you want to arrive about an hour before low tide so you have time to hike the trail (about a mile through mossy forest), cross the sandbar, explore the island, and get back before the water rises. Don't cut it close. Bring shoes you don't mind getting wet. If you time it right, pair it with Settlement Quarry on the way back — it's a short detour and doesn't depend on tides. If the tide window is afternoon, flip the order: quarry first, Barred Island when the sandbar opens.