Commuters at the World Trade Center Transportation Hub Oculus will no longer have exit the building to connect to an E train.

The Port Authority opened access to the E line from within the Oculus on Monday. The entrance is located on the hub’s second level in the northeast corner.

It retains some of the “historical features” that existed before the 9/11 attacks, like the original limestone flooring, doors, directional signage and a ramp structure from the entryway, according to the Port Authority.

“The opening of the new E subway entrance culminates a year of activity in which the World Trade Center Transportation Hub Oculus opened in phases,” the agency said in a press release announcing the news.

A section of the over-budget, $4 billion Oculus hub first opened to the public this March. The remainder of the Santiago Calatrava-designed structure opened in May. The hub already connects PATH riders to 10 New York City subway lines, including 2, 3, 4, 5, A, C, J, Z, R and W. An additional connection to the R and 1 trains will be opening in the coming months, the agency said.

The World Trade Center hub is the busiest PATH station, serving 54,573 riders, and many more shopping tourists, on an average weekday, according to 2016 Port Authority data through November.

The new E entrance is not ADA accessible, but the agency said that it would be building an ADA entrance “in the future.”