Named for (what very little is left of) the sea-polished glass in the sand, remnants of its days as a city dump, this beach is now part of MacKerricher State Park. Take the headlands trail from Elm St, off Main St, but leave the glass – visitors are not supposed to pocket souvenirs.
Be wary of the tides here, and there can be big waves and an undertow. A safer beach to swim is just north at Pudding Creek Beach.