The New York City subway system is one of the oldest in the world. The first underground line from City Hall to the Bronx opened in 1904.

Today, the New York City subway is one of the largest and most complex systems of its kind, operating over 842 track miles, and serving the four boroughs of Manhattan, Queens, Brooklyn and the Bronx. It operates 24 hours a day, serves 468 stations on 26 interconnected lines, and averages 5 million passengers each weekday.

Not impressed yet? Try this one. New York’s subway system carries more passengers each year than all the other mass transit rail systems in the U.S. combined.

Now for the downsides. A New York subway is far from the cleanest. It’s definitely not the sleekest. Its hard plastic seats are clearly not the most comfortable. And the smells that sometimes waft from the nooks and crannies of the subway stations are not the most pleasant.

But there’s something special to me about New York City’s subway. It has a bit of charm thanks to the mosaic tile art that you’ll find in each station. Some of the art dates back to 1904. The artwork is unique to each station and centers around the station’s name. Sometimes you’re treated to other little splashes of tile art like the pink hat I am “wearing” in the photo above.

The Metropolitan Transportation Authority’s Arts for Transit program oversees the subway art, which also includes sculptures, murals, and live musicians.

Some of my non-New York City friends turn their noses up at the thought of taking the subway in any city, especially in New York. They think it’s beneath them. Well, it is, literally of course.

What they are missing out on is what I and millions of other New York City subway passengers know. It’s the quickest way to get around the city. It’s the cheapest way to travel. And it’s the most green way to travel when you compare it to all of the above-ground options.

But it also provides an opportunity to experience art on a whole new level — that is, the art of the underground.