[One World Trade Center. Via One World Observatory]

In the year since we last looked at the status of the World Trade Center complex, much progress has been made: One World Trade Center welcomed its first tenants, the observatory atop that glassy building opened to the public, and the transit hub beneath the site inched ever-closer to completion. While there is still work to be done to complete the 16-acre site, it's that much closer to becoming a reality. (And that's not even taking into account developments that are separate from the complex, like Brookfield Place and the soon-to-be-headquarters of Time Inc.) As we approach the 14th anniversary of the September 11 terrorist attacks, we're taking another look at the WTC campus to see what progress has been made, and what remains to be done.

More World Trade Center coverage:

Nearly All World Trade Center Relics Have Found a Home

A Guide to All the Megaprojects Transforming New York City

Inside the Still Unfinished $4 Billion WTC Transportation Hub

Remembering The Twin Towers As A Fixture Of The Skyline

One World Trade Center

The crown jewel of the complex, One World Trade Center officially opened for business on November 13, 2014, welcoming anchor tenant Condé Nast to the building. Things haven't exactly been perfect: Rats were spotted at the magazine publisher's offices last year, and as of May, the building was still 37 percent unrented. But hey, even the Empire State Building had problems getting filled when it opened. Meanwhile, One World Observatory, located at the very top of the building, opened to the public on May 28, offering panoramic views, virtual ride through history on the elevator, and dining options (though perhaps it's better to skip those). Though the building managed to convince the Council on Tall Buildings and Urban Habitat to list it as 1,776-feet-tall and the tallest building in the country, its roof has since been surpassed by that of residential tower 432 Park Avenue.

2 World Trade Center

Also known as 200 Greenwich Street, 2 World Trade Center doesn't yet exist, yet it is the building that has undergone the most change since this time last year. The widely praised design by Norman Foster of London-based Foster + Partners has been scrapped in favor of a more box-y design by Danish architect Bjarke Ingels. There's a stair-step facade with green balconies at each setback that faces east, and a more traditional glassy curtain wall that looks west, toward the 9/11 Memorial, One World Trade, and the Hudson River. The building will be about 80 stories tall and rise 1,340 feet (nine feet shorter than the old design). The foundation has actually been in place since 2013, but investors are still being sought for the tower, which is estimated to cost $4 billion. It could be complete by 2020.

3 World Trade Center

While this Richard Rogers-designed tower languished at several stories tall for years, developer Larry Silverstein secured financing and construction has resumed. However, the design for the building, located at 175 Greenwich Street, has changed a little. The masts that would have brought the height to 1,168 feet have been eliminated, bringing the height down to 1,079 feet. No word on why they were dropped, though the building stands out less for it. It now stands at over half of its final height. It's expected to top out in 2016, have glass in place in 2017, and be open for business in 2018.

4 World Trade Center

Designed by Fumihiko Maki of the Tokyo-based architectural firm Maki & Associates, 4 World Trade Center, located at 150 Greenwich Street, was the first building to open in the new WTC complex. It tops out at 977 feet and 72 stories, and the architecture world absolutely loved the design. One critic called it "shimmering perfection" and the American Institute of Architects honored it in its annual awards. Tenants started working in the building on October 27, 2014, though there was little fanfare when compared to the subsequent opening of One World Trade. Tenants at 4WTC include the Port Authority and the financial research firm Morningstar.

[Old rendering for 5 World Trade Center (right).]

5 World Trade Center

Also known as 130 Liberty Street, this site—once where the Deutsche Bank Building stood—is one of the less talked about pieces of the World Trade Center puzzle. It was originally planned as the 42-story headquarters of JPMorgan Chase, but that fell through and construction of the Kohn Pederson Fox-designed building is currently on hold. KPF might not even end up being the architect behind whatever eventually is built there, if anything is even built. The Port Authority has not made a final decision and there is no date for the future of the project.

[7 World Trade Center. Photo by Sweenyr via Wikipedia]

7 World Trade Center

Things remain just about the same for this building. Located just north of the World Trade Center, 7WTC shares the complex's name, but is technically separate from the 16-acre development. Having opened in May 2006, it was the first tower rebuilt after the attacks. Standing 741 feet tall and designed by a team from Skidmore, Owings & Merrill, it sits on the same site as the old 7 World Trade Center. It was fully leased as of 2011.

The 9/11 Memorial

Much remains the same at the 9/11 Memorial, which opened on September 11, 2011, although there's now a proliferation of selfie-stick–wielding tourists on the memorial plaza on the regular. But it's getting closer to the architects' previously stated goal of making it a public space for both visitors and locals: Tickets were previously needed to visit the memorial, but after the surrounding barriers were removed last spring, people can now just walk in off the street, even at night.

National September 11 Memorial Museum

The museum devoted to preserving artifacts connected to the site's history and the 2001 terrorist attacks is almost entirely underground. After some delay, it was dedicated on May 16, 2014 and opened to the public on May 21. Like the memorial pools above it, the size of the museum is incredibly impressive. Unfortunately, it was recently reported that the slurry wall, which holds back the Hudson River (and which survived those devastating atacks), is leaking. There is a concern that any necessary repairs could delay development of commercial space.

World Trade Center Transportation Hub

The long-delayed transit hub is finally making some progress. The Oculus, the 150-foot-tall winged structure designed by Spanish architect Santiago Calatrava is nearing completion, and portions of it are already open to the public. The skylight within the structure will open every year on the anniversary of the terrorist attacks. As for the rest of the transportation hub, the Port Authority currently lists a 2015 completion date on its website, though readers who travel through the space regularly say that date has been pushed back to 2016 and references to 2015 have been edited out of banners there. Still, that is at least eight years behind schedule and $2 billion over budget. Once it's completed, it will connect the PATH trains, 11 subway lines, World Trade Center towers 1-4, the 9/11 Memorial, Brookfield Place (formerly the World Financial Center), and the Battery Park City ferry terminal. It will also hold 225,000 square feet of retail space.

[The now scrapped Frank Gehry design for the performing arts center. Via Gehry Partners.]

World Trade Center Performing Arts Center

Both the anticipated name and the architect of record for this project are no longer. Frank Gehry, who was commissioned to design the cultural space, was fired from it last year (the center's president says the split was "amicable") and no new design has been announced. And now, the center is now going by PAC WTC (pronounced "Pack W-T-C"), though its owners are open to corporate sponsorship. One big problem: A budget cut, with the center's original budget slashed in half to $200 million. David Lan of the Young Vic in London was hired to run PAC WTC, which is supposed to have three combinable theaters and a public space open from 8 a.m. to 1 a.m. The center could be open in 2018 or 2019.

St. Nicholas Greek Orthodox Church

Commercial buildings weren't the only structures to fall during the attacks: St. Nicholas Greek Orthodox Church, located at 155 Cedar Street, was also destroyed. Calatrava was selected to design a new church at 130 Liberty Street, and construction is officially underway, with the foundation poured just last month. Construction on the small project, which will be located at the east end of Liberty Park, is expected to take about two years.