The World Trade Center's rebirth began Wednesday with the grand opening of the first tower on the 16-acre site.

Elected officials, residents and business leaders joined Silverstein Properties, the building's developer, for 4 World Trade Center's opening. Although the 977-foot building pales in comparison to its neighbor, 1 World Trade Center, which was officially named the tallest building in the Western Hemisphere at 1,776 feet Tuesday, Mayor Michael Bloomberg said it was still an important symbol for downtown Manhattan.

"We're no longer looking forward to the future of the World Trade Center because a part of the future has arrived," he said.

The glass office skyscraper won't have its first tenants, the Port Authority of New York and New Jersey and the city's Human Resource Administration, until 2015, but it features amenities for visitors. The lobby will have an overhead sculpture that is still under construction and three interactive video art walls that play images of trees, water and sky.

A terrace on the 57th floor features stunning panoramic views of the entire Manhattan skyline and parts of New Jersey and Brooklyn.

Tenants on the other floors will get the full 360-degree view.

Silverstein Properties founder and CEO Larry Silverstein remarked that visitors who take in those sights will see a downtown Manhattan that's revived immensely since the 9/11 attacks.

"The World Trade Center is living up to the ideals we all set forth," he said.

Fumihiko Maki, principal of Maki and Associates, the architectural firm that designed the tower, said he wanted his project to blend in with the rest of the community, especially the 9/11 Memorial.

He noted that he designed the building to draw visitors to the site and honor the victims of the attacks.

"It is and continues to be a special privilege to contribute to the rebuilding of lower Manhattan," he said.