* "Landmark" is broad: It could mean a building, a natural feature, a monument, or something else entirely.

* An acre is a large area: It's roughly the size of a football field.

So, finding a landmark that's *exactly* one acre is unlikely.

Here are some possibilities:

* Small historical sites: Perhaps a small battlefield or the foundation of a historical building could be close to an acre.

* Parks: Some very small urban parks might be around an acre in size.

* Monuments: A large monument, like a statue or obelisk, could occupy a space close to an acre if it has a significant base or surrounding grounds.

To give you a better answer, I'd need more information:

* What type of landmark are you looking for?

* Where in the world are you interested in?

With more specifics, I can help you find a more appropriate landmark!