Eight-year-old Beck Dalton went to the Navy Yard on Saturday morning in search of big Spider-Man energy, and he wasn’t disappointed. The cloud-colored tunnels, fashioned from packing tape and suspended in the middle of Building 694, could easily pass for giant webs that had just sprung from the superhero’s wrists and were hanging there, frozen in time.

Inside the cocoon, Beck crawled in sock feet on hands and knees, the floor bouncing and crackling. The outside world was distorted by the walls, which are built from layers and layers of tape.

“It feels kind of normal in there, but then you can’t see the scenery where you are,” he said.

Tape Philadelphia: Enter the Cocoon, an art piece made of tape, opened to the public in Building 694 at the Navy Yard in Philadelphia on Saturday.
BAIDI WANG / Staff Photographer
Tape Philadelphia: Enter the Cocoon, an art piece made of tape, opened to the public in Building 694 at the Navy Yard in Philadelphia on Saturday.

Beck and his parents, Dahvia and Drew Dalton, who live in Queen Village, were among the first visitors to Tape Philadelphia: Enter the Cocoon, an installation that opened to the public Saturday morning in a cavernous warehouse on the grounds of the Navy Yard. The project was commissioned by ​Group X​, the anonymous collection of Philadelphia-based artists, curators, and organizers who brought last year’s popular Sea Monster installation to another vacant Navy Yard building.

The installation is free, and attendees can reserve time slots online or simply walk in. Visitors must remove their shoes, then climb a steep ladder and through a portal, after which they have five minutes to explore. Only five at a time are allowed inside the cocoon, which is built from 21.5 miles of tape and can withstand about 2,000 pounds.

Michael Insogna and his family get ready to enter the 128-foot cocoon.
BAIDI WANG / Staff Photographer
Michael Insogna and his family get ready to enter the 128-foot cocoon.

“The way the light comes in is beautiful,” said Sylvia Insogna, of Old City, who visited with her husband and their two children Saturday morning.

“It’s kind of like you’re in a snow cave, or an ice cave, or in a glacier,” said her husband, Michael. (Adding to the effect, the warehouse is unheated.)

“Can we come here every Saturday and Sunday?” asked their 6-year-old daughter, Viviana.

Viviana Insogna, 6, stands inside the cocoon.
BAIDI WANG / Staff Photographer
Viviana Insogna, 6, stands inside the cocoon.

Saturday reservations were filled, meaning more than 300 visitors were expected on the first day. The installation is open through Dec. 1. Facilitators said they will go over it inch by inch at the end of each day, patching minor tears like a Zamboni machine smoothing ice.

The surface is wobbly, like a trampoline, and slippery in spots. Some areas drop off steeply into narrow tunnels that veer toward the ground.

Michael Insogna Jr., 9, climbs the ladder after his sister Viviana.
BAIDI WANG / Staff Photographer
Michael Insogna Jr., 9, climbs the ladder after his sister Viviana.

“There’s an element of danger, or the perception of it,” said George Alley, an artist and professor at Temple University, who toured the cocoon twice on Saturday. “It’s like a fortress of solitude. It really takes you out of your surroundings."

Matthew Ray, the creative director of a local marketing company who visited with Alley, said he wanted to go back in as soon as they finished their first crawl-through.

“Your sense of scale is thrown off, your sense of balance is thrown off, the sound is different in there,” he said. “It’s an incredible sensory experience. It’s amazing to feel that sense of wonder.”

Hours are 4-8 p.m. Thursday; noon-8 p.m. Friday; 10 a.m.-8 p.m. Saturday; and 10 a.m.-5 p.m. Sunday. To reserve time slots and for more information, go to navyyard.org/cocoon.