Children in hard hats dug their pint-sized shovels into Smurf-colored sand Friday, officially launching construction on the new home for the San Antonio Children's Museum.

The 5.5-acre site on Broadway at Mulberry, the former site of an old car dealership, will be transformed into a state-of-the-art, 65,000-square-foot playhouse of curiosities.

It will feature much more outdoor space and more parking than the current Houston Street location.

"Perhaps more than anything, the content will be evolving a little more toward math and science because that's what teachers tell us we need to focus on the most," said Vanessa Lacoss Hurd, executive director of the Children's Museum.

The new exhibits will feature an engineering studio where children can tinker, a sensations lab to help children understand the physics behind what they see, hear and feel, and a little town where children can role-play.

"It makes learning fun," said Mayor Julian Castro. "If you truly want kids to absorb knowledge, the best way to do that is when they are having fun learning."

The kids were having fun at the groundbreaking, watching a geyser created from Mentos and soda, and making handprints in plaster molds.

The demonstrations were an example of the laboratory and sense of discovery the museum will offer.

The newer, more centralized location is expected to draw more visitors, increasing annual admissions from 170,000 to 300,000 in the first year.

The new location is across the street from Lion's Field and down the street from the Witte Museum. The McNay Museum and San Antonio Museum of Art are nearby, as well.

"Broadway has become this museum district, this corridor of creativity, and the Children's Museum will complement that very well," Castro said.

The $46 million project is 90 percent funded, according to Hurd. City bonds worth $3 million were dedicated to the  museum. The remainder is from private and corporate donations, including $4 million from Valero and $20 million from HEB CEO and philanthropist Charles Butt.

Completion is estimated at spring of 2015.

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