by John McDevitt

PHILADELPHIA (CBS) — The Philadelphia Zoo continues to work on a network of see-through trails, allowing animals to move long distances through — and above — its campus.

Today, following a ribbon-cutting ceremony for the latest enclosure extension for big cats, two Amur tigers — Wiz and Demetri — took a stroll on “Big Cat Crossing,” fourteen feet above visitor’s heads.

It’s the latest pathway of the animal trail system known as “Zoo 360.”

“As we expand Zoo 360 across our whole 42 acres,” said Philadelphia Zoo president and CEO Vikram Dewan, “we will continue to advance this mission: providing our animals and our visitors experiences not available at any other zoo in the world.”

Construction on sections of the trails began in 2011, initially allowing animals such as goats, miniature horses, monkeys, lemurs, and orangutans to travel within the system.

More animals will get access in a couple of years as the network expands.

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