The Esplanade provides opportunities for many activities

The Charles River Basin looks to all appearances like the most visible and carefully preserved natural feature of Boston. Nothing could be further from the truth. In the nineteenth century the shallow basin, its nine-mile length edged with broad salt marshes from Watertown to Boston Harbor, was dammed for mills and filled for commercial and residential ventures. The bays of the lower Charles at low tide became vast expanses of stinking, sewage-laden mud flats.

Not until the end of the century did the citizens of greater Boston take the first steps to clean up the river and transform its shores. Today nothing remains of the tidal estuary that was once the lower Charles – the margins of the Basin are an entirely man-made landscape. Though manmade—and in that sense artificial—the Basin is also a wildlife habitat for hundreds of animal and plant species that play a role in the ecology of the region and enrich the experience of urban park users. Water quality in the once heavily polluted Basin has improved dramatically in recent years, creating better habitat for wildlife and attracting people back to the river.

The character of the Basin changes upstream at the BU Bridge, where the river narrows. From the Charles River Dam to the BU Bridge the Basin is two and one-half miles long and up to two thousand feet wide. The panoramas define the image of Boston and Cambridge. Sweeping views of the skyline from the seawalls are captivating. The Longfellow Bridge is a powerful presence, as are the slope of Beacon Hill and the gold dome of the State House.

Upstream the river becomes more rural and natural

Particular park sections within the Reservation, such as the Teddy Ebersol Red Sox Field, Magazine Beach, and Herter Park, provide intensely used open space for the bordering urban neighborhoods. The Storrow Memorial Embankment – universally known as the Esplanade – was dedicated in 1936, and provides opportunities for walking, biking, running and roller-blading along leafy paths. The Hatch Shell on the Esplanade attracts hundreds of thousands of people to special events each year, including the Boston Pops concert every Independence Day.

From the BU Bridge to the Watertown Dam is a zone of transition from urban and formal to rural and natural. Parkways lining the Charles River Basin separate it from contiguous open spaces. The largest open space is between the Harvard University athletic fields on the south and Mt. Auburn and Cambridge cemeteries on the north. Together, these areas form a critical oasis for migrating birds.