Recently I visited every gallery in the main building of the Metropolitan Museum of Art—in a single day. In today's Wall Street Journal, I describe what it was like to see over four hundred galleries, and just what I discovered on this Grand Tour.

I knew it would be a challenge. There are tens of thousands of objects on display out of more than 1.5 million in the permanent collection, overseen by 2,200 employees and 17 curatorial departments. They are spread across some two million square feet of space occupying two-plus floors, and housed in over 400 galleries, period rooms, and installations—a mind-boggling array. A few weeks earlier, when I asked Thomas P. Campbell, the Met’s director, how long it would take to see every room, he said: “Two years.

Nonetheless, I was determined. So on a recent Friday, a bit past 10 a.m., I arrived at the main entrance on 82nd and Fifth Avenue, armed with a pen, a notebook and a good pair of sneakers. I bounded up the stairs and into Richard Morris Hunt’s ethereal 1902 Great Hall. I helped myself to a museum map, and made a right for Gallery 100, the beginning of the Egyptian wing and the first in the Met’s numbered sequence of galleries.

Catch the entire piece here.