The 20-acre North Bank Bridge Park project, located in Boston, Charlestown and Cambridge, Mass., reclaims a derelict underbridge space overwhelmed by vestigial industry, highway ramps, and the looming Zakim Bridge and transforms it into a safe, vibrant, welcoming, aesthetically pleasing and fun Underbridge Plaza, that gently tames its gritty urban character while still honoring it. It is the last park built within the New Charles River Basin, a formerly inaccessible portion of the Charles River on both the north and south banks, referred to as "The Lost Half Mile." The North Bank Bridge Park created the first river-edge connection between the Charles River and the Boston Harbor, finally fulfilling a century-old vision of Charles Elliot. Landscape Architecture firm, IBI Placemaking completed the project in 2012.

Underbridge Plaza and a New Paradigm
A key feature of the Park is the Underbridge Plaza, an unexpected urban outdoor room that borders on the Charles River and utilizes the Zakim Bridge as its roof. The landscape architects saw an opportunity to create a new kind of urban public space, which responds directly to the extant urban industrial setting and the sleek monumentality of the sculptural bridge and highway infrastructure. Though this approach challenged the initial direction provided by the client and the Citizens' Advisory Committee, which was to move people through the space as quickly as possible, the landscape architects prevailed in promoting a memorable urban plaza beneath the Zakim Bridge. The uncluttered space allows for such unanticipated uses as dog walking, joggers performing morning calisthenics using the low retaining walls, cycle clubs holding dance parties, people offering marriage proposals, and film shoots for luxury car ads, giving evidence to the fascination and appeal this space holds for the public.

 

In the Underbridge Plaza, the linear paving design reflects linear folds in the underside of the Zakim Bridge. Landforms, which help to guide circulation, transition from soft to hard as they slip under the Bridge. The landscape architects invite the public into the Underbridge Plaza using subtle uplighting, while also establishing clear sightlines into and through the Plaza. To celebrate the verticality of the surrounding concrete highway piers, and to give a sense that "the lights were on," the landscape architects conceived of vertical light pylons to "occupy" and animate the Underbridge Plaza, a concept implemented in collaboration with an artist.

Connections and an Icon
The North Bank Bridge, the project centerpiece, spans the Millers River, a commercial Duck Boat launch, and the MBTA commuter rails to create vital pedestrian and bicycle connections between Cambridge and Charlestown. It also creates a lively sculptural element within the park, an iconic piece of bridge architecture that complements, rather than competes with the even more iconic Zakim Bridge. The landscape architects worked with the bridge designer to develop the bridge's reverse curved horizontal alignment to create a seamless interface with approaching park pathways, while creating a dramatic view centered on the Zakim Bridge's north pylon.

Sustainability
Part of reclaiming this urban waterfront entailed using rigorous sustainable measures, such as native planting to restore parts of the riverbank and form the east abutment of the North Bank Bridge, the reclaiming of stone seawall blocks and granite cobblestones from other parts of the Central Artery project, and coordinating a complex brownfield reclamation effort that consisted of removal and capping of various on-site contaminated materials.

Conclusion
The planning and design for the North Bank Bridge Park, which took nearly a decade, was guided by the overriding conviction that the public would one day be thrilled to come into this new realm, to see the city from a new vantage point and to appreciate the unique experience of being "up close" with the colossal Zakim Bridge structure.

As seen in LASN magazine, April 2020.