A python-length alpenhorn rang out over the undulating terrain of Fairmount Park on Saturday to mark the start of renovations at the historic Smith Playhouse children’s activity center, aided by a $1 million donation from a Swiss billionaire with Philadelphia ties.

Michael Pieper made his contribution to an $8.5 million effort to fix water damage that has long kept part of the 120-year-old building’s basement off limits, while transforming that subterranean space into an upgraded tricycle-riding zone with a section carved out for a new nature-oriented preschool.

Also planned are new restrooms for visitors to the indoor and outdoor sections of the Smith Memorial Playground and Playhouse complex, on 6½ acres of East Fairmount Park. The playground may be best known as home to the giant enclosed wooden slide that kids — and the stray adult — spin down on burlap sacks.

"We are thrilled to be able to further the wonderful work that Smith has been doing for the past 120 years, and to ensure that future generations will be able to play, learn, and grow at Smith,” Pieper, president and chief executive of the Aarburg-based Artemis Group, said in prepared remarks.

The complex was founded at the end of the 19th century by the Richard and Sarah Smith Trust to provide Philadelphia children with a place for supervised play in an era of child labor.

In 2003, when the trust’s resources proved too meager to keep the playground and playhouse from falling into disrepair, a nonprofit support group was formed to carry on the work.

Since then, the group has overseen the slide’s restoration, repairs to the playhouse, replacement of outdated playground equipment, and the introduction of such features as a separate section for children under 5.

The work that formally began Saturday is slated to conclude in August 2020 with new bathrooms, fresh paint, and upgraded electrical work throughout the playhouse, a three-story, 16,000-square-foot brick-and-masonry structure filled with toys, blocks, puppets and other play objects.

Most of the restoration work, however, will take place in the basement, which will house the new Urban Nature Preschool and the upgraded “Smithville” tricycle course.

The preschool will be built around a curriculum that emphasizes connections with its parkland surroundings, said Deborah Green, executive director of the Parent Infant Center in West Philadelphia, which was selected to operate the new school.

Children will learn math by counting acorns and listen “to beautiful children’s literature under the trees,” she said at Saturday’s ceremony.

Playhouse and school leaders are still working out how much it will cost to attend, but plan to ensure that half of the seats go to families with low-enough incomes to qualify for tuition subsidies, said Smith executive director Frances Hoover.

Other contributions to the renovation efforts, dubbed the Preserving Play Campaign, included a $1.3 million grant from the William Penn Foundation and city and state funds.

Pieper said he made his contribution as a way of showing his appreciation and affection for Philadelphia, where he first came to in 1978 to attend a three-month finance course at the University of Pennsylvania’s Wharton School.

He remained in the city for six years, first working for the Philadelphia National Bank, then co-founding a company that bought troubled firms and returned them to solvency to profit from their resale.

He later returned to Switzerland to assume leadership of Franke Holding AG, a maker of kitchen sinks and other industrial-grade kitchen equipment, from his father.

Franke is now a subsidiary of Artemis, a conglomerate that is one of the world’s major suppliers of stainless steel kegs, linoleum, and other products. Pieper’s real estate holdings include stakes in such Philadelphia commercial properties as the Wells Fargo building at Fifth and Market Streets.

Pieper said he and his wife, Emmy Lou, decided to focus their largesse on the playhouse-restoration campaign at the request of his friend Hanley Bodek, a developer who sits on the Smith board.

“I took Michael and Emmy Lou down the giant slide,” said Bodek, founder of the Philadelphia Construction Co. “And they were sold.”