A groundbreaking ceremony was held Wednesday for Legoland Discovery Center Boston in Somerville, said Merlin Entertainments, an operator of visitor attractions. One ceremonial highlight: A front-end loader dropping 50,000 Lego bricks on the site where the center will be built.

Plans call for a 44,000-square-foot indoor attraction that is geared toward children aged 3 to 10 and their families. It will feature millions of Lego bricks, some of them engineered to be duplicates of Boston landmarks, and the center “will offer a fun, highly interactive and educational two- to three-hour indoor experience,” Merlin Entertainments said.

Scheduled to open in May, Legoland Discovery Center Boston will be the first and only such center in New England and it will employ a staff of about 100, the company said.