Beverly Pepper’s “Manhattan Sentinels” stand guard over Federal Plaza. The thirty sculptures, over 36 feet tall, are arranged in groups of three throughout the plaza to resemble trees. Richard Serra’s “Tilted Arc” was formerly located near where Pepper’s sculptures are today and divided the plaza, but Pepper created her massive steel sculptures with the intention to create an environment and that “Manhattan Sentinels” would become part of the landscape. Pepper, born in Brooklyn in 1922, has been working in steel and other metals since she and her husband moved to Italy in 1956. Despite her age, Pepper is still an active sculptor.