Tessie is not your average greeter.
The 20-foot-tall giraffe, created from a ton of plastic bricks, stands ready to welcome children and other visitors to the newest Legoland Discovery Center, which is scheduled to open May 23 at Assembly Row in Somerville and is already sold out through the first three days.
The huge indoor facility covers 44,000 square feet and features 11 attractions, from rides to a 4D movie theater with sensory effects. It sounds like a children’s fantasy world — which is why Legoland has placed a ban on adults who aren’t accompanied by a youngster.
But the Lego Group itself is hardly kids’ stuff. The company, based in Denmark, is one of the world’s top toy makers, with $4.6 billion in annual sales in 2013. Legoland parks, which were acquired by British-based Merlin Entertainments in 2005, are such big draws that the Somerville center is considered a key anchor tenant of the new $1.5 billion Assembly Row mixed-use development along the Mystic River. It’s expected to draw Lego-obsessed youngsters — and their parents — from all over New England.
“We’re now a destination from Vermont to Rhode Island,” said Russell Joyner, a vice president and general manager of Federal Realty, the developer of Assembly Row.
This is the sixth Legoland Discovery Center in the United States. Worldwide, there are four more, along with six outdoor Legoland theme parks.
Once inside the Somerville complex, visitors will be funneled through a massive cutout of a Lego figure that doubles as a doorway, and then lifted by a set of elevators to the starting point of what is billed as a Lego Factory Tour.
The tour is also offered at most of the other Legoland Discovery Centers in the United States, but the Boston version is more interactive and the first to provide a virtual visit to the actual Lego factory in Billund, Denmark.
In the tour, mini-Lego figures Bertie and Bonnie appear on four 13½-foot screens placed along the walls of a circular room. Children can create their own digital minifigures by selecting from an assortment of head, body, and leg pieces that are displayed on the screens.
On the Kingdom Quest Laser Ride, children can ride in chariots and shoot laser guns at “trolls” on digital screens to save a captured princess. In another area of the Somerville facility, visitors can build and race their own toy cars.
A cinema at the center will show Lego films in 4-D — that means they will be augmented with sensory effects such wind, rain, snow, or lightning strikes. For example, when it snows in the film, artificial flakes may fall on the audience. During blustery scenes, wind machines blast the crowd with air.
The complex also includes Lego models of historic Boston landmarks, such as Fenway Park, the USS Constitution, and Paul Revere’s house. It is the largest “miniland” section of all the Legoland Discovery Centers, according to company officials.
Parents, be forewarned — you will be unlikely to exit Legoland without spending more money. The way out leads visitors through a 2,000-square-foot retail store stocked with 500 Lego products, including a kit to build a Volkswagen bus for about $120 and a Lego model of the home of television’s Simpsons family that sells for $200.
Children can also fill a cup with their choice of 90 Lego pieces — for a price — from a “pick-a-brick” wall in the store.
Admission to the complex is $18 for children age 3 to 12, and $22.50 for anyone 13 or older. Children under 3 will be admitted free of charge. Annual passes start at $70 for an individual and go up to $260 for a family of four.
“It’s a timeless toy,” said Kelly Smith, a spokeswoman for Legoland Discovery Center. “It’s one reason why the Discovery Center and Legoland parks are so popular.”
Oh, and for those childless grownups who also like timeless toys, you aren’t being shunned altogether. The center will host an adults-only evening on the third Wednesday of each month, starting in June.