The phrase "a vast zoo" is correct and usable in written English.
You can use it to describe a large and diverse collection of animals in a zoo or metaphorically to refer to a wide variety of things or people.
Example: "The city has a vast zoo that attracts visitors from all over the country, showcasing animals from every continent."
Alternatives: "a large zoo" or "an extensive zoo".
In the 1503 watercolor "Virgin and Child With a Multitude of Animals and Plants," he turns the world into a vast petting zoo.
A vast complex complete with a zoo, it was destroyed in the early 20th century by a series of fires.
Born and raised in a northern Rangoon slum, he has yet to visit any of the city's grandiose new monuments — a vast pagoda, a much-touted zoo, a gem museum.
Special attractions include the dolphin shows in the Seven Seas exhibit (Brookfield was the first inland zoo to build a dolphinarium), a children's zoo, and Tropic World, a vast enclosed exhibit of mixed species from the three main rainforest habitats of the world (African, Asian, and South American).
In a searing article in US News & World Report, journalist Michael Satchell described "a little-known practice by some of the nation's premier zoos: dumping surplus, old, or infirm animals into a vast, poorly regulated -- and often highly profitable -- network of substandard, 'roadside' zoos and wildlife dealers who supply hunting ranches and the exotic-pet trade".
He bribed authorities, ordered killings and, at his peak, lived with the improbable trappings of a Charles Foster Kane: His possessions included submarines, a fleet of airliners and a vast estate, Hacienda Los Nápoles, complete with a private zoo.
It also has impressive grounds, with a vast garden, a 27-hole golf course and even a petting zoo, complete with llamas who presumably feel as at home in the Alps as the Andes.
Participants quickly discovered that the YCBA has a vast collection of exotic animals, they just aren't quite as smelly or noisy as the animals at the zoo.
It is a vast organisation.
