The 13-acre Acacia Grasslands would cover the current south parking lot and include a 6-acre mesh flight cage, which designers say would be the biggest aviary in the U.S. Giraffes could lope through grasslands while flamingos flew overhead. Platforms might allow visitors to feed giraffes; glass walls in a new restaurant would cozy up to the lions, just outside.

Legends of the Forest would renovate the current snake and primate buildings with bubbled domes over forests, swamps and raised walkways.

The plastic domes insulate, but also let light through, designers said. Retractable sections could give the monkeys and apes access to fresh air, while still protecting animals and visitors from bad weather — a perennial handicap for zoo attendance in winter.

“No more keeping primates in dark corners,” designer Becca Hanson told the zoo board on Wednesday.

The Silk Road would feature hillsides and canyons, with snow leopards, takin, red pandas and even giant pandas, though McGuire called them “a long shot.”

New to the St. Louis Zoo: Tasmanian devils The sisters’ arrival marks the first time in 30 years that the St. Louis Zoo has cared for this endangered species.

“We’re trying to be aspirational,” he said.

As a whole, the renovations would lead the visitor through a trail of exhibits and “organize the adventure a little more,” McGuire said.