Drop in on a free summer yoga session from 6 to 7:15 p.m., every Thursday through August 30, at Frog Pond (next to the carousel) on Boston Common. Instructors (an eclectic mix of writers, musicians, athletics, cyclists, runners and more) welcome students of all levels. Bring your own mat, blocks, towels and belt.

Cost: Free. Location: Frog Pond on Boston Common, 38 Beacon St., Boston (nearest T station: Green Line/Park).