It's been a dozen years now since the non-profit organization 4heads has invited independent artists to come to Governors Island and fill those stately old mansions of Colonels Row with their work. 4heads cofounder Antony Zito says that this year, they received more applications than ever to be a part of the show, and the quality of proposals was also exceptional, leading to many agonizing arguments among the jurors over who should be included.

The end result of all that time and energy is Portal: Governors Island, a sprawling, instantly engaging, and often provocative art fair opening this Saturday and running every weekend through September. As has been the custom in recent years, Portal has taken over four of the historic brick homes on Colonels Row, and each of the nearly 100 artists included in the fair are given a room—or a kitchen, or a hallway, or a stairwell, or a closet, or a porch, or a spot on the front lawn—and are allowed to do whatever they like with it.

Everything is for sale—that's why it's called an art "fair"—but the artists don't pay a fee to exhibit here, nor are there any gallerists working on commission, so that part of the process is all very low key. And it's relatively affordable, if you're in the market. Either way, many of the artists hang out in their areas throughout the fair, especially on opening weekend, and they're always willing to chat with you about the work if you're so inclined.

There are sculptural pieces, paintings, installations, mixed-media stuff, animations, conceptual work, and show-stoppers of all varieties. With this many artists, and this much art, you will obviously respond to some things more than others—one of the great pleasures of Portal is the sense of surprise inherent in the layout, as you never know what's through each door, or around each corner.

But a few of my favorite pieces would include Bobby Anspach's crazy pom-pom cave (see the video above), into which you enter with another person, get completely geared up, and lose all sense of space as you stare into each other's eyes. My other favorite was Jiwon Rhie's "Flower Dogs" (see the video below), for which she unleashes dozens of those yippy little battery-operated puppies, all covered in plastic flowers, into one of the kitchens. It made me smile every time.

I also really liked "Locked and Loaded" by Kimberly Walker, a mountain of padlocked army-green duffel bags with their corresponding keys rendered useless, embedded in a block of concrete, and the way Sam Sundius sewed her own hair into her "Toaster" pieces. The ghostly black-and-white photos by Phenomena Lewis dominate the front room of one of houses, and Unhee Park does the same thing with her flattened domestic scene, featuring five cats. Kyle Luntz's mechanical music boxes are fun to play with, Xiaoyue Liu's "Where Did All the Squirrels Go" features some cute (though deceptively dark) computer animation, and Kerry Lessard's birthday-themed series of paintings deserve a nice long look.

The piece you're most likely to see on Instagram, the giant dog made from plastic bags on the front lawn, comes from Will Kurtz. Sherri Hay's "Time and Empathy" is a "very slowly moving object," propelled by the gradual release of sand, and takes between four and six hours to unfold. And Elisha Grant's "Sick Bed" is a startling installation littered with Oxy bottles, paper prescriptions, and a death certificate. There's a lot more to explore, most of it good, and the entire exhibition will take you at least two hours to walk through. It's an excellent reason to get over to Governors Island one last time before summer is gone for good.