The phrase "a large complex of" is correct and usable in written English.
It can be used to describe a significant and intricate system, structure, or group of related elements, often in contexts like architecture, biology, or social sciences.
Example: "The city features a large complex of interconnected parks and recreational facilities that promote community engagement."
Alternatives: "a vast network of" or "a significant system of".
The Lakeland Center is a large complex of venues hosting sporting events, theatre productions, concerts, and trade shows and conventions.
I walked into a park, toward a large complex of restaurants that lay in front of a shallow but wide pool, blue, with peeling paint.
Behind it, on Tiffany Street, a large complex of brick buildings is being renovated for condominiums, and others are going up throughout the neighborhood.
The site runs from 43rd to 51st Streets, between the waterfront and a large complex of buildings and warehouses known as Bush Terminal.
The Imperial Cormorant is part of a large complex of marine shags of the Southern Ocean; species-level relationships in the group are still being resolved.
The best-known of these is Rock Eagle in central Georgia, a large complex of quartz rocks laid out in the shape of a bird.
It is now part of a larger complex of buildings known as the International Shakespeare Globe Centre.
The facilities that reported the accidents have a notorious past, having once been part of a larger complex of Soviet laboratories and testing facilities devoted to the science of biological warfare.
Songs for curing rituals are often learned as part of a larger complex of knowledge requiring an apprenticeship; the student receives direct instruction from an experienced practitioner over the course of several years.
And the aesthetic is more than skin deep -- it feels more like a component of a larger complex of creature comforts that places like San Juan can provide on the cheap.
We don't have anything like the full story of the CIA's involvement in torture, and the CIA is only one agency within a larger complex of agencies, military and civilian.
