'monumental project' is correct and usable in written English.
You can use it to describe an ambitious or complex task that has long-lasting significance and impact. For example: "This revolutionary new energy project is a monumental project that could change the energy landscape for decades to come."
His monumental project, Roden Crater, remains unfinished.
To finance his monumental project, Curtis needed sponsors, and to attract them he had gorgeous prints made for various exhibitions.
His second offering in this monumental project, "Illinois" (Asthmatic Kitty), is a 22-song swing through Prairie State history.
The second volume in this monumental project will cover the next 100 years, during which, despite huge physical changes, many of the city's attributes have remained unaltered.
"The Yale Edition of Horace Walpolers Correspondence", is a monumental project, organized by Lewis in 1933, & since directed, edited & financed by him.
I was eagerly awaiting the next publication, as Peter was an almost permanent fixture at the British Library researching his latest monumental project on the blues.
It's still an enormous project, but Ward distinguishes between "myopic monumentalism" and monumental projects done right.
Even the Army Corps of Engineers concedes that its costly and monumental projects along coastlines like this one are ultimately fruitless.
Much as for large architecture firms, his team helps him raise funds, but also designs and produces increasingly monumental projects.
Like other artists of his generation – James Turrell, Alice Aycock, Robert Smithson, Walter de Maria – Heizer spurned the gallery for the landscape, and started undertaking monumental projects directly in the earth.
But the container with all the paintings and the wooden models of the Kabakovs' often monumental projects remained somewhere in Germany.
