It’s hard to be an “under the radar” destination in the vicinity of the Acropolis in Athens, but if anything comes close, it might be the Roman Agora, which is just to the north of the Acropolis. While its neighbors like the Ancient Agora, the Stoa of Attilus, and the glut of awesome museums in the area might garner a lot of attention, the “Horologion” of the Roman Agora is one of the most unique and interesting ancient buildings on the whole continent. There’s really nothing else like it.

It’s sometimes called “the Tower of the Winds,” and I’ll tell you why in just a moment. First, some background. “Agora” is the Greek word for “gathering place,” and in ancient times, the Agora was essentially the Greek equivalent of a Roman Forum. It was a marketplace, a meeting place, a space for politics and debate, and pretty much any other public function you can imagine. The Ancient Agora of Athens is the oldest, and biggest, dating all the way back to the 6th century BCE. By the time the glory days of Athens were over and the Romans had taken over, it was still the central forum space of the city. That didn’t stop the Romans from doing their own construction, though, and the cluster of public buildings built by the Romans right next door to the original Agora a few hundred years later eventually came to be called, fittingly, the Roman Agora.

There’s not a whole lot left in it, but there’s still plenty that catches the eye, like the Gate of Athena Archegetis, which was a gift to Athens from the Caesers Julius and Augustus, and a 17th century Ottoman mosque that was just recently restored and opened to the public. The real highlight, though, is the aforementioned Horologion, the Tower of the Winds. It’s a really interesting building aesthetically, as you can see by the picture. Each of the structure’s eight sides correspond to a cardinal direction—north, northeast, east, etc—and each side is decorated at the top with a frieze depicting the ancient Greek spirit that represented the wind of that particular direction. In ancient times, the building was topped off by a big weathervane in the shape of the god Triton, as the romans may or may not have believed that the direction of the wind could predict the future.

Beyond that, what’s really interesting is that it might also be considered the world’s first true clock tower! If the four faces of Big Ben impress you, you’re in for a treat. Horologion literally translates to “time-keeper,” and that was the tower’s primary purpose back in the old days. The entire building was a giant sundial, and in case of a rainy day, that weathervane at the top contained a water clock running down into the building so the ancient Athenians could keep all their appointments. It’s an interesting example of how these big, public structures built by the ancients had more than symbolic value—in a time a couple thousands of years before the watch was invented, the people and the government needed to do a lot more work to ensure public life ran as smoothly as possible, and buildings like the Horologion are fun, monumental examples of how public utilities can be something both useful and poetic, in a way. It’s not at all out of the way or time consuming, so if you’re doing any the standard Acropolis and Agora touring packages, it’s definitely worth checking out.