A 128-foot-long cocoon has taken over a vacant warehouse at the Navy Yard, and its creators — artists, not insects — want you to crawl through its suspended passageways.

Opening to the public Saturday, the massive installation, Tape Philadelphia: Enter the Cocoon, was commissioned by ​Group X​, the anonymous group of Philadelphia-based artists, curators, and organizers who brought last year’s popular Sea Monster installation to town, at another vacant Navy Yard warehouse.

» READ MORE: An inflatable sea monster takes over the Navy Yard

Sea Monster, with its huge, inflatable purple tentacles reaching through the windows of a World War II-era structure, was designed by the street art duo Filthy Luker and Pedro Estrellas, based in the United Kingdom. It drew about 60,000 visitors.

This time, Group X called on Numen/For Use, an experimental European arts collective that has created large-scale site-specific projects in Moscow, Berlin, Seoul, and other cities.

One of the collective’s specialties is making installations out of tape. Its Philadelphia Cocoon hangs 18 feet in the air inside Navy Yard Building 694, like something out of a Spider-Man movie, and uses 21.5 miles worth of translucent tape.

It has two openings. One is a portal where visitors can climb a ladder into the heart of the cocoon and explore; five people will be permitted inside at one time. (Free reservations can be made online at navyyard.org/cocoon.) The other is designed to let visitors with disabilities see inside without needing to climb up.

“Last year, people came down to see the Sea Monster and they’d spend 40 minutes hanging out — everything from picnicking to getting engagement photos in front of it — but it was just something fun and silly to look at. We didn’t expect that level of engagement,” said a member of Group X. “This time, we wanted to do something more interactive, that people could actually soak into.”

Step up into the cocoon and it feels a little like you’re in a treehouse with your grade school friends. You crawl around inside on hands and knees. (Standing is prohibited.) Bright white walls surround you, glistening when the sun shines through the south-facing windows above.

“On one hand, it’s this oversize cocoon, a place where you feel protected. But on the other hand, you’re a little insecure by it being this sticky tape. It creates an interesting juxtaposition,” said Christoph Katz, one of the three artists in the Numen/For Use collective. “Tape, this super-normal, everyday material, can hold an enormous force, though.”

It took a dozen people layering tape strand after tape strand for 12 days to bring the design to life. Group X engaged consultants, including a structural engineer and a welder, to asses the installation’s strength. The building entrance is ADA compliant, and the installation has the required short-term occupancy permit from the Department of Licenses and Inspections.

“A lot of people in Philly don’t get out to the galleries or museums because there are so many barriers to art — whether social, economic, or physical,” said the Group X member. “Our goal with Group X is to create art that’s accessible to everyone and to create art for art’s sake. Art doesn’t always need to have a history lesson or push a particular agenda.”

Tape Philadelphia: Enter the Cocoon is free. You must be taller than 40 inches to explore inside the artwork. You’ll need to remove your shoes, and socks are required. Children younger than 11 must be accompanied by an adult.

“Building 694 has been mostly vacant since 1996,” said Navy Yard spokesperson Jennifer Tran. "It’s incredible to see it come to life again.”


Tape Philadelphia: Enter the Cocoon

From Nov. 9 through Dec. 1 inside Building 694 at the Navy Yard, just past the Broad Street entrance at 1701 Langley Ave. (Closed Nov. 17 and 28.)

Hours: 4-8 p.m. Thu.; noon-8 p.m. Fri.; 10 a.m.-8 p.m. Sat.; and 10 a.m.-5 p.m. Sun. Lights will illuminate the structure at night.

Information: Visitors are encouraged to make a free reservation to enter the interior of the cocoon. Without a reservation, interior access may be restricted or require a long wait time. Reservations can be made online at navyyard.org/cocoon.