Boston — a colonial city crossed by a 21st-century bridge

Boston was founded in 1630 when eleven ships carrying roughly 700 Puritan colonists, led by John Winthrop, crossed from England to settle a peninsula the local settler William Blaxton had already been living on. Nearly four centuries later, that same colonial core still anchors one of the country's oldest cities — the Freedom Trail alone links sixteen Revolutionary-era sites, from the Old North Church to Faneuil Hall, over 2.5 miles of downtown streets.

Rising over the Charles River just beyond that historic core is something entirely modern: the Leonard P. Zakim Bunker Hill Memorial Bridge, opened in 2003 as the centrepiece of the Big Dig, Boston's decades-long project to bury the elevated highway that had once sliced through downtown. Designed by Swiss engineer Christian Menn, its ten lanes are held up by 116 cables strung from two towers deliberately shaped to echo the nearby Bunker Hill Monument, making it one of the widest cable-stayed bridges in the world.

What the three cameras show

Boston beyond the webcams

Freedom Trail: a 2.5-mile route linking sixteen Revolutionary-era sites through downtown Boston and Charlestown.

Boston Public Library: opened in 1848, the first large free municipal library in the United States, built on the principle "Free to All."

Charlestown Navy Yard: home to the USS Constitution, reachable on foot from the Zakim Bridge's pedestrian path.

When to watch

Zakim Bridge, sunset: for the white cables glowing against the Boston skyline as evening settles over the Charles River.

Getting there: the Museum of Science sits on the Charles River Dam, a short walk from North Station and the Zakim Bridge, Boston, Massachusetts, USA.