Our Thursday evening practice, and some one-day retreats (zazenkai), are held at

Friends Meeting at Cambridge, 5 Longfellow Park, Cambridge, MA 02138 (map).
We usually met in the “Friends Room” which is in the Friends Center building (on map as “Friends Meeting at Cambridge”).
Sometimes we meet instead in the “meetinghouse” (on map as “Material Aid and Advocacy Program”).

For clarification:

Our multi-day retreats (sesshin), and some one-day retreats (zazenkai), are held at