Built 2004. Description: A three-block-long walkway lined by nearly 200 trees, the Promenade spans the center of Millennium Park from Monroe to Randolph streets. Chicagoans and visitors are invited to enjoy exhibitions, festivals and other family events on these eight acres of parkland. The new Boeing Galleries add much-needed formal space for public exhibitions to the park's mid-level terraces. The Galleries are lined on either side by a row of graceful sycamore trees - a rarity in Chicago. Additional seating is provided by a series of black granite steps - matching the granite of The Crown Fountain - along each gallery's east side, while a pre-cast concrete staircase connects the south Gallery with the beloved fountain. The mission of the Boeing Galleries is to be a democratic and compelling destination for modern and contemporary art, where the public can directly experience the work and ideas of living artists, providing a high quality historical, social and cultural context of the art and architecture of our time. Size: 24.5 acres