Art museums

What was the last art museum built with that classic “art museum” look (i.e., big stone building with steps and columns in the front)?

The wonderful Cleveland Museum of Art, built just over a century ago?: Cleveland Museum of Art - Wikipedia

How about the Lady Lever Art Gallery near Liverpool, opened in 1922? Construction began in 1914, just a year after Cleveland’s started, so it’s pretty close between those two.

Adding a nominee to my own OP, the National Gallery of Art in Washington opened in 1941.

National Gallery of Art

While the Cleveland museum does have that classical portico, the building has been expanded multiple times, and the current main entrance is in a much more modern-styled wing. And I expect that something similar will be true of many other musea. Does that still count?

Most modernist galleries are modelled on grain silos.

Is that a deliberate reference to Le Corbusier?

Partially, but not only…
Here is the new Kunstmuseum of Liechtenstein. Image.

Here is a Danish Cement Silo. ** Image.**

I’m not sure what you’re looking for but how about the Getty Villa, which opened in 1974?