It's no surprise that art connoisseurs regularly flock to New York for a fix of what's hot or just to revisit timeless classics -- the Big Apple is the definitive art capital of the United States. But beyond Fifth Avenue, Chelsea and Long Island City -- indeed, an hour north of the George Washington Bridge -- there are treasures to be found upstream.

Far from the city lights, in the rolling hills of the Hudson Valley, lie two bona fide sanctuaries of modern art. One is Storm King Art Center, a mecca of monumental sculpture spread out over 500 manicured acres, where you're just as likely to catch an exhibition of works by a mid-century great as that of an established sculptor of our time.

A half-hour east, across the river, is Dia:Beacon, the flagship exhibition space of the Dia Art Foundation. The museum is remarkable -- and not just for its must-see-before-you-die permanent collection. The serenity of the space, nurtured by natural light that radiates in through the roof, left me marveling that it was once a Nabisco packaging plant.

Leaving the cityscape, my husband and I were surprised at how quickly the peaceful upstate countryside came upon us. (Rejoice that the city isn't more car-friendly: Eight million weekenders on wheels would surely drown out the rustle of the forests.)

We headed for Storm King first, in Mountainville. Most of the drive north was along I-87, until our trusty GPS directed us onto the kinds of curvy county routes reserved for car commercials.

Off the interstate, it's typical New England; landscapes straight out of the region's better-known 19th century artistic heritage, the Hudson River School. Winding roads pass mailboxes marking the beginnings of long driveways hidden by dense, protective trees.

Also hidden from view was our turn for Storm King, which we nearly missed, had it not been for the insistent voice of our GPS. Then, one by one, some of the largest sculptures we had ever seen began revealing themselves along the grounds as we drove up to the hill-top gallery.

Upon reaching the elevated vantage point of the center's main gallery and admissions office -- the grounds' only indoor shelter -- the view morphed from surprising to astonishing. The surrounding hills and valleys are dotted with massive sculptures, more than 100 in all. Buffered by forests on all sides, we couldn't feel further from the "civilization" just an hour south. It was time to explore the art.

The seemingly endless expanse of the grounds requires enthusiasm, walking shoes and a few unencumbered hours. We weren't able to cover enough ground to examine each piece up close, but that's not the point; these pieces aren't meant to be analyzed with a microscope. This is art at its largest, and it strikes from a distance.

Indeed, many of the sculptures at Storm King really only make sense from afar, such as Israeli artist Menashe Kadishman's "Suspended," which creates an optical illusion: One of the two steel blocks that make up the piece stands a few feet uphill, while the other half, on a lower plane, rests against it. The unbroken green groundcover makes the trick work, leaving the viewer to wondering if the higher portion is somehow suspended.

Works by Mark Di Suvero, whose studio fronts the East River in nearby Long Island City, are ubiquitous at the park -- and a natural fit. Peeking well above the foliage, his massive, sometimes complex, configurations of steel command the space around them.

Just about every master of large-scale sculpture is well represented in Storm King's permanent collection: Alexander Calder, Richard Serra, Isamu Noguchi, Ursula von Rydingsvard, Kenneth Snelson -- the list goes on and on.

With sculpture, the scale of the surroundings is always tricky: Too much space can dwarf a piece, too little can cramp it. Sculptures of this magnitude truly only find their natural habitat in a setting such as Storm King. It is one of very few sculpture parks of its kind in the world, and we felt privileged to have experienced it.

After powering up the GPS again, getting to Beacon from Storm King was easy. The half-hour ride flew by as we passed through Beacon, a gritty little town with all the markings of a past steeped in industry.

In 2003, Dia opened its contemporary museum at the former factory, listed in the National Register of Historic Places. The space is an homage to the artists whose works the foundation has championed since the 1960s and to say it does them justice is an understatement.

Dia is perhaps best known for helping artists create and preserve some of the most demanding, far-out artworks on Earth, including Robert Smithson's "Spiral Jetty" and Walter De Maria's "Lightning Field," both outdoor works where the land is part of the art. It made no exception with Dia:Beacon.

Upon entering the museum, you are greeted by De Maria's "Equal Area Series," an installation of flat, stainless-steel circles and squares spanning the floors of two narrow, adjacent galleries -- a rare commitment of square footage. If you weren't aware of how seriously the foundation takes its collection, now you know.

After overcoming the impact of that enormous and visually stunning installation, there's plenty more to see: rooms dedicated to works by Joseph Beuys, John Chamberlain, Dan Flavin, Andy Warhol; walls of drawings by Sol Lewitt; an entire wing for Richard Serra's "Torqued Ellipses."

For me, though, the cherry on top of all this was another only-at-Dia:Beacon installation: Michael Heizer's "North, East, South, West." Dug several feet into the museum floor, these conical and rectangular negative spaces are going nowhere and beg to be seen from as close as Dia will allow.

For all the allure Dia:Beacon and Storm King hold for art lovers worldwide, their distance from the city keeps the throngs comfortably at bay. We were able to stroll and admire the art at our own pace at both venues, sharing a gallery at Dia:Beacon with perhaps one or two people at the same time -- something you'd have to have amazingly good connections to experience at places like Manhattan's Guggenheim or Metropolitan Museum of Art.

Leaving Hudson Valley behind, we felt reinvigorated and committed to seeing more of this level of art and exhibition quality. But we have our work cut out for us; Dia and Storm King set the bar at a height we never imagined. It will take quite some searching to match it.

IF YOU GO:

• Best for: Art lovers and anyone visiting New York City with a couple of days to spare.

• Getting there: From LaGuardia or JFK, rent a car and drive about an hour north, up I-87, to Mountainville and Beacon.

• Cost of a weekend getaway: Car rentals tend to be pricey coming from New York airports ($70-$100 per day for a compact), but much better deals can be had at non-airport locations; book early.

WHERE TO STAY:

• Cromwell Manor Historic Inn: Blending modern accommodations with colonial-style decorations and furnishings, this bed-and-breakfast in Cornwall is near Storm King Art Center and also hosts art workshops on occasion, should you decide to explore your own creativity. Rates $165-$380. 174 Angola Rd., Cornwall; www.cromwellmanor.com, 845-534-7136.

• Mt. Beacon Bed & Breakfast: This cozy but elegantly decorated three-story mansion minutes from Dia:Beacon boasts a three-course, gourmet breakfast. Rates, $165-$195. 829 Wolcott Ave., Beacon, www.mtbeaconbedandbreakfast.com, 845-831-0737.

WHERE TO EAT:

• Cold-Spring Depot, 1 Depot Square, Cold Spring; 845-265-5000; www.coldspringdepot.com. Comfort food is the order of the day at this local, family-oriented joint. Its uncomplicated but bountiful offerings, including chicken pot pie ($9.95) and crab-stuffed portobellos ($9.95), won't leave you guessing. Dinner entrees, $16.95-$23.95.

• The River Bank, 3 River Ave., Cornwall-On-Hudson; 845-534-3046 or 866-767-BANK; www.theriverbank.biz. Go for the view, or the casual menu that ranges from Italian brick-oven pizza ($10-$13) to sesame chicken with peanut sauce ($20).

• Schelsinger's Steak House, 475 Temple Hill Rd., New Windsor; 845-561-1762; www.schlesingerssteakhouse.com. Carnivores can splurge on such hearty entrees as "pub steak," served with caramelized onions, mushrooms and bleu cheese ($23.95), or the "Schlesinger" -- a 20 oz. rib-eye ($24.95). Seafood, $19.95-$33.95. Smokers can digest at the restaurant's cigar bar after dinner.

VISITING THE ART CENTERS:

• Storm King Art Center, Old Pleasant Hill Road, Mountainville; 845-534-3115; www.stormking.org. Catch a special exhibit of Sol Lewitt sculptures through Nov. 15. The center is closed in winter. Admission, $10 adults, $9 students, $7 for K-12 students, free for ages 5 and under.

• Dia:Beacon, 3 Beekman St., Beacon; 845-440-0100; www.diaart.org. The museum offers tours of Heizer's "North, East, South, West" before it opens, 10:30 to 11 a.m.; reserve in advance. Special events this summer include a performance by the Merce Cunningham Dance Company, July 6, and a gallery talk on Andy Warhol, July 26. Admission, $10 adults, $7students, free for under 12.

INFORMATION:

• Hudson Valley Tourism, www.travelhudsonvalley.org, 800-232-4782.