Two projects totaling $1.2 billion that will bring 831 more high-end condominiums and apartments to Boston’s Seaport District are marking construction milestones.

Boston-based developer Cronin Group held a ceremonial groundbreaking Monday for the St. Regis Residences, a 22-story waterfront condo tower on the former Whiskey Priest and Atlantic Beer Garden properties at 150 Seaport Boulevard.

The Elkus Manfredi-designed tower containing 114 condos will be managed by Marriott International’s St. Regis brand.

Construction of the $260 million project was delayed in 2017 when the Boston-based Conservation Law Foundation claimed the project violated the state’s Chapter 91 waterfront access act by not providing sufficient public access to Boston Harbor. The two parties settled the lawsuit in January after Cronin Group agreed to pay $18.5 million toward a public dock, off-site waterfront park, funding for Martin’s Park on Fort Point Channel and enrichment programs for local youths.

Totaling 263,000 square feet, the project will include a walkway that wraps around the harbor side of the building, eliminating a gap in the Boston Harborwalk. Resident amenities include a swimming pool, spa and health club.

The late Howard Elkus, a principal and co-founder of Elkus Manfredi, said in 2015 that the twisting glass facade was designed to become a landmark on Boston Harbor.

Across the street, developer Cottonwood Group marked the completion of the steel framing for its $950 million EchelonSeaport project last week. Three residential towers are rising above a 125,000-square-foot retail podium on a 3.5-acre site formerly used for surface parking.

Designed by CBT Architects, the project will contain 447 condos and 270 luxury apartments, with resident services provided by Regent Hotels & Resorts. Completion of the first condo building is scheduled for fall 2019.