Spectacle Island, a Boston landfill until 1950, has become one of the world’s best troves of sea glass. Beginning today, a conservation group plans to make the island and its gleaming treasure a classroom.

Pictured: BJ Clark, Carolyn Burkett and Thi Tran, youth workers from Save the Harbor/Save the Bay, collected sea glass and artifacts on the beach from the island's days as a dump.