The Bronx and Manhattan have a new connection that has been 45 years in the making.

The city reopened the redesigned High Bridge, the oldest bridge in the city, to pedestrians and bike riders Tuesday.

Elected officials from both boroughs joined residents who waited years to take in the sights from the 1,450-foot long walkway and enjoy a quicker commute for pedestrians between Washington Heights and Highbridge section of the Bronx.

"High Bridge links us between our great history and bright future," said city Parks Commissioner Mitchell Silver at yesterday's ribbon cutting.

The bridge was built in 1848 over the Harlem River as a link in the Croton Aqueduct system, bringing freshwater from upstate to the five boroughs. Engineers didn't want the structure to interfere with ships so the bridge stood 123-feet high.

For more than a century, New Yorkers would use the bridge to commute between the Bronx and Manhattan, however decay and poor maintenance forced the city to shut access down in 1970.

That didn't stop community activists from pushing the city to restore, and reopen the bridge for access.

"It needed to be open because it helped to bring back history to the public's attention," said Charlotte Fahn, of the Friends of the Old Croton Aqueduct, one of the groups who called for the restoration.

The city undertook several studies, and in 2007 Mayor Michael Bloomberg announced it would repair the bridge for pedestrian use. During the three-year, $61.8 million construction project, crews repainted the steel span, installed an eight-foot safety fence, built accessible ramps and put in new lighting.

"This is almost like the eighth wonder of the world," Manhattan Borough President Gale Brewer said.

The city also added new amenities to High Bridge Park in Washington Heights, which serves as an entry point for the Manhattan side of the bridge. The 130-acre green space includes updated ballfields, a mountain bike trail and a public pool.

The first group of people to traverse the walkway said it was worth the long wait.

"I've been biking for years and this is the best ride I've taken in a while," said Jose Baez, 42, of the Bronx as he rode his two-wheeler from the Manhattan side to the Bronx side for fun. "It'll be a great shortcut for me."

The community groups will hold a celebratory party for the reopening on the walkway on July 25.

Elected officials said they hope that fanfare will give a major boost to both communities located near the bridge and park. The neighborhoods have seen a surge in younger residents along with new developments and businesses.

Bronx Borough President Ruben Diaz Jr. predicted the walkway will be the first of other projects that help put a spotlight on the Bronx and Washington Heights that preserve their character.

"Downtown Manhattan has the High Line, but uptown Manhattan, we have the High Bridge," he said.