[5] With the project later renamed Wynn Boston Harbor,[8] around 30 of those acres had previously been set aside for industrial use and were inaccessible to the public for more than 100 years.

[11] Wynn's rival bidder Mohegan Sun also sued the commission, demanding a do-over of the casino license competition.

[18] On January 5, 2015,[5] Wynn Resorts spent $35 million purchasing[17] 33 acres of land along the Mystic River in Everett, announcing plans to develop "an integrated resort containing a hotel, restaurants, casino, spa, premium retail offerings, meeting and convention space and a waterfront harborwalk.

[21] On September 10, Wynn Resorts rolled in equipment and workers to begin site preparation and pre-construction activities.

[21] Site remediation officially started in the third week of October, with Charter Contracting Company, LLC hired to conduct the initial four-month cleanup process.

Wynn Resorts paid the $30 million estimated remediation costs directly, as compared to using public funds.

[26] Beyond several casinos, Suffolk had previously constructed projects such as the Mandarin Oriental, Liberty Hotel, and the Boston Opera House.

Revealing a 100 square foot model of the resort, Wynn asserted they were aiming for a July groundbreaking, with the cost of the project upped from $1.7 to $2 billion.

[38] The name of the project was changed to Encore Boston Harbor as part of an effort by Wynn Resorts to distance itself from its founder.

[38] In April 2019, the Massachusetts Gaming Commission assessed a $35 million fine for failing to disclose years of sexual misconduct allegations against Wynn Resorts, but cleared the way for the casino to open on June 23, 2019.

[40][41] As of May 2024, Wynn was negotiating with the city of Everett in hopes of building a $400 million expansion of gaming, restaurant, and nightclub space on the east side of Broadway, connected by an overhead walkway.

[42] Wynn has already purchased for $25 million 45 acres of land from Constellation Energy, where Mystic Generating Station is being decommissioned.

[43] According to the Encore Boston Harbor website, the 33-acre development is "the largest private single-phase construction project in the history of the Commonwealth of Massachusetts.

[44] With 671 rooms,[1][45] the building houses a hotel and gaming area[24] as well as a five-star spa, meeting, and event space with a grand ballroom,[18][45] while the lobby used to feature a 2,000-pound (910 kg) sculpture of Popeye by artist Jeff Koons,[18] which Steve Wynn purchased at auction for $28.2 million[46] specifically for the location.

[50] The resort features a number of venues, retail outlets, and other attractions beyond a hotel, including a casino, thirteen restaurants,[52][53][54][55][56] a sports bar, a spa, and space for meetings and weddings.

[57] At opening day the following 15 bars and restaurants were available: The development features the harborwalk, which includes a public park and boardwalk situated between the Encore Boston Harbor skyscraper and the waterfront of the Mystic River.

[3] In August 2015, Wynn Resorts stated that it intended the harborwalk to be "Boston's most magnificent outdoor gathering spot.

"[20] Public amenities include a picnic park, paths for bikers and pedestrians, viewing decks, waterfront restaurants and retail,[2] a performance lawn, floral displays,[6] and boat docks.

[2] The harborwalk and trails connect pedestrians with the neighboring Gateway Center Park,[20] Wynn Resorts also agreed to subsidize the Orange Line that crosses over the river from nearby Somerville to Medford,[30] paying for improvements at the nearby Sullivan Square station[60] and Wellington station.

[61] Wynn operates free shuttles to the Wellington and Malden Center Orange Line stations,[62] free neighborhood runners from Everett, Chelsea, Chinatown, Dorchester, Quincy and Lowell,[63] and a $7 shuttle to and from Patriot Place in Foxboro, Massachusetts (the location of Gillette Stadium, home of the New England Patriots American football team).

As of October 2019, negotiations are underway on access rights and construction funding, which might come from the casino, the gaming commission, the MBTA, or the cities of Everett or Somerville.