Playground

"What is this place?" "First thing I found on that box was these coordinates. Another secret base?"

- Melinda May and Phil Coulson

The Playground is a former Strategic Scientific Reserve facility that was renovated to become a top secret S.H.I.E.L.D. facility at a classified location. After the S.H.I.E.L.D. Civil War and upon Phil Coulson becoming director of S.H.I.E.L.D., it became the headquarters for the new S.H.I.E.L.D.

History
During World War II, the Playground was a bunker base belonging to the Strategic Scientific Reserve. Agent Peggy Carter used this base to hold her documents on prisoners such as Werner Reinhardt in its vaults. Before 2014, Nick Fury refurbished it with modern technology.

Rebuilding the Agency
Phil Coulson was given a Toolbox to aid him in his mission of rebuilding S.H.I.E.L.D. from scratch after Fury appointed him as the new director. The first thing Coulson found in the Toolbox was the coordinates to this secret base.

Upon arriving, the team met Jemma Simmons, having been dropped off by Fury. The team was also greeted by Agent Billy Koenig, identical brother of Eric Koenig who was stationed at Fury's other secret base, Providence.

Over the next few months, Coulson spent little time in the Playground as he tried to find agents for S.H.I.E.L.D.; he would travel the world and would mostly communicate via viewscreen. He tasked Skye with translating the Words of Creation and Leo Fitz with giving the Bus cloaking technology. Eventually, he recruited Alphonso Mackenzie and the mercenaries Isabelle Hartley, Lance Hunter, and Idaho. Before Jemma Simmons was sent on an undercover mission to infiltrate HYDRA as one of its scientists, Coulson had her stationed to watch Grant Ward, their prisoner in Vault D in the basement of the Playground.

While Billy Koenig was away, Coulson ordered an inventory of the Playground and caution on the amount of fuel being expended.

Mackenzie won a bet against Hunter, causing Hunter to do inventory. Coulson complained to May that he felt that he wasted fuel on his trip to retrieve Agent 33 because HYDRA obtained her first.

Leo Fitz learned that Grant Ward was locked in a cell in the Playground's basement.

After Phil Coulson and Melinda May returned from their mission in Miami, Florida, they informed Glenn Talbot that there was a HYDRA agent impersonating him. However, he was more interested in trying to trace the call.

Lance Hunter convinced Skye to talk to Grant Ward in Vault D about the Words of Creation. Their conversation makes Skye realize that Coulson was now carving the Map. When she confronted him, they were interrupted by Raina's phone call. When she confronted him for a second time, he gave full disclosure. He showed her his carving and told her that he has no idea about its meaning. Skye revealed that the symbols were a map.

Meanwhile, Jemma Simmons arrived at the Playground after being rescued from HYDRA Laboratories by Bobbi Morse and Antoine Triplett. Fitz greeted her with hesitancy.

Skye watched Grant Ward exercise in his cell as Simmons told her about when she was his watcher. Their conversation was interrupted by Melinda May telling them that the United Nations was attacked. Director Coulson sent Bobbi Morse, Lance Hunter, and May to Japan to follow a lead on the attack while Simmons solicited help from Leo Fitz to get more information from the hard drive that was procured from HYDRA Laboratories. Skye and Coulson watched a televised debate between Senator Christian Ward and Belgian Foreign Minister Julien Beckers railing against S.H.I.E.L.D. He asked her to get information from Grant about Christian but that discussion began to digress to one about her father. After Coulson saw the Senator personally, Grant Ward was transferred into federal custody.

Coulson soon learned from May that Noelle Walters and her team of agents were killed by Marcus Scarlotti and his mercenaries.

Grant Ward escaped federal custody and went to Philadelphia to get resources. Director Coulson told Agent Antoine Triplett to bring Ward in alive, by any means necessary. However, Triplett saw Ward's bombs and was redirected to observation.

Ultimately, Sunil Bakshi was captured by Melinda May and brought to the Playground for interrogation. As Skye probed Bakshi's phone, Ward called it to tell her that he will send her more presents like Bakshi.

May then opened the Playground's Vault B, to look into documents relating to Whitehall's connection to the Red Skull.

Trivia

 * Though in a classified location, it is likely that the Playground is located in Virginia. Unlike Coulson's previous secret base, Providence, which was hidden deep in the wilderness, the Playground appears to be hidden in plain sight, seemingly in an old industrial/warehouse complex. Also, unlike Providence, which was completely underground, certain parts of the Playground are above ground, while most of the base is underground.
 * It appears that the Playground was redesigned between Season One and Season Two as the appearance of the hanger in Beginning of the End, is significantly different than the hanger shown in Shadows and subsequent episodes of the second season.