The phrase "a true landmark" is correct and usable in written English.
It can be used to describe something that is significant or noteworthy, often in a historical or cultural context.
Example: "The new museum is a true landmark in the city, attracting visitors from all over the world."
Alternatives: "a significant milestone" or "a notable landmark".
It may have been all about ownership, but here lay a true landmark of national surveying.
But it is a true landmark, as for the first time it offers a route to the solution, and for that we should all give thanks.
Wooden chairs, lantern lights and a balcony make the theater a true landmark, and at $3.50 a ticket, an inconceivable bargain.
The introduction of a national living wage was a true landmark in the history of Conservatism and, potentially, of the country.
Alasdair Morrison, chairman of MG Alba, said: "Launching BBC Alba on both the Freeview and cable platforms is a true landmark for Gaelic broadcasting.
A powerful expression of both loss and hope, Britten's War Requiem was a defining work not just for him but for twentieth century music, a true landmark in the choral repertoire.
Ludicrous as "Fear Factor" was -- especially coming from NBC, whose president has declared "The Sopranos" too vulgar for network TV -- it was but a blip on June 11 next to the Timothy McVeigh show, a true television landmark.
The concert "is destined to a be a true Boston landmark," added Taylor.
Ask a jazz aficionado or cabaret regular and they'll tell you that Birdland is a true New York landmark.
Honored 2 be part of grand opening 2day for revived @dchowardtheatre in Shaw, a true cultural landmark.
If the Allstate plaintiffs prevail, the case could give older workers their first true landmark case, with damage awards large enough to make corporate America recalculate the costs of discriminating.
