Endurance is a quality shared by the turtle sculptures in this post. Lilli Ann Roseberg’s colorful concrete turtles in Cambridge have been ridden, jumped on, snowed in, flooded over and lots more in the past three decades. Nancy Schön’s bronze Myrtle the Turtle was bound up and relocated within Boston’s Myrtle Street Playground soon after settling in last year. These sculptures endured isolation while playgrounds were closed in the spring and then cautiously reopened.