TRAVEL WRITERS LOVE TO IGNORE the obvious. In the well-trampled territory of Texas, this can produce some pretty squirrelly results—like the national magazine that recently said the state’s best beach was on Lake Travis. And yes, even I have spent more time than I care to admit trying to whip up enthusiasm for, say, the scenic beauty of cactus-riddled Sanderson. But let’s face it. Some places remain tourist-free for reasons that have nothing to do with being undiscovered.

And then there’s the San Antonio River Walk, an attraction so alluring that it’s often buried beneath a writhing mass of humanity. Every time I’m in San Antonio I swear I won’t go there, and every time, there I am, dodging bulging fanny packs and grackle poop, bedazzled by the end result of architect Robert H. H. Hugman’s vision for a Venetian-inspired Paseo del Rio. Construction began in the thirties, and the charm—along with a wee bit of schlock—has been layered on ever since. No two of the original 31 stairways are alike, and the bridges range from a few late-nineteenth-century iron structures—whose builders sent cavalry troops charging across them to test their strength—to arched stone footbridges, magnets for lovey-dovey couples. Fountains, tile murals, benches in cozy niches, and plaques commemorating historic sites pop up around every corner. Such unlikely botanical bedfellows as palm, cypress, lime, and magnolia trees cram the lush banks, and even in mid-winter, bougainvillea, elephant ears, and ferns thrive in protected spots.

Oodles of hotels have also sprouted along the River Walk. I’m partial to those that complement the romantic ambience, like the venerable, Spanish Colonial-style La Mansión del Rio—built around an 1852 Catholic school, with balconies overlooking the central hubbub—and the atmospheric Havana Riverwalk Inn, on a quiet northern stretch of the river. But the buzz about the Hotel Valencia Riverwalk, which opened one year ago, was so intriguing that I decided I had to check it out.

With its ocher and umber stucco exterior, circular tower, and multiple levels, the hotel sits on the river like a Tuscan villa that expanded over generations. But crack open its Mediterranean facade and you’ll find an interior that might have been designed by an Asian playboy with a James Bond fetish. The minimalist public spaces are all concrete walls, bold fountains, splashes of red carpet, boxy leather chairs, dark wood, and chrome-bead curtains. Cool, man.

The swinging-bachelor theme continued unabated in my room, with its faux-mink throw and eight-foot-tall framed mirror leaning against the wall. But the designer-playboy hadn’t given much thought to the bathroom, which, while stylish, was disappointingly dinky. And the feather pillows were so hard I thought they were stuffed with whole geese. All was forgiven, however, after one touch of the Poggesi Italian linens. Best of all was the balcony overlooking the River Walk, where I ate fresh raspberries for breakfast, one of my favorite hedonistic pleasures.

The Valencia is pricey, but its location is premium. You can march four blocks to the Alamo, sashay one block to catch a performance at the over-the-top Majestic Theatre, restored to its 1929 splendor, or stroll three blocks to admire the $5.8 million renovation of the elaborately adorned San Fernando Cathedral, parts of which date back to 1738, making it the oldest continuously operating Catholic sanctuary in the United States.

Starry-eyed affection for the river was effortless on the balmy, not-too-crowded Sunday I was there in November. But as I sat in a far corner of the open-air patio at Boudro’s on the River Walk, eating guacamole smashed tableside, watching the people parade, and pondering why so many muscleless men wear muscle shirts, I wondered if my feelings would change if I came here when the river is drained for its annual maintenance (this year, January 5 through 12). Sure, I’d be able to get a table at any restaurant at any time. And I’d probably have the roving mariachis all to myself. But would that be enough?

To find out, I pretended the river was empty. Just imagining its silty bottom littered with cell phones and water moccasins was enough to motivate me to leave this man-made playground to seek the waterway’s more natural side. After consulting San Antonio on Foot, by Diane Capito and Mark Willis, I struck out for the University of the Incarnate Word, where, in a secluded corner of the campus, I found the river’s historic source, bubbling away at the bottom of a limestone well. The spring—once geyser-strong but now sometimes dry—is called the Blue Hole, and blue it was, a dazzling aquamarine I associate with gemstones I can’t afford. And I’m not its first admirer. The area is lousy with evidence of prehistoric residents. Archaeological sites on the campus have yielded wooden tools and stone points, some dating to 11,000 years ago, when mastodons and giant bison roamed the neighborhood. A few yards south of the Blue Hole (a.k.a. the San Antonio Springs), the flow joins Olmos Creek to form the San Antonio River.

Like the River Walk, San Antonio’s famous Spanish Colonial missions also owe their existence to the river, whose waters irrigated 3,500 acres of farmland that provided their food. Some local friends had mentioned a hike-and-bike trail that runs along the river between the missions, and I thought it might be the perfect route to discover this less frivolous aspect of the waterway’s personality. But while the missions log more than 1.4 million visitors annually, and the Missions Trail roadway is well-marked, the Missions Trail hike-and-bike path seems to be a well-kept secret. The folks at the San Antonio Visitor Information Center knew nada, and there’s no sign of it on the official San Antonio Missions National Historic Park map. (I later learned that only one sixth of the twelve-mile, multimillion-dollar project has been completed, so I guess its current low profile is understandable.)

All this mystery only made me more determined to find it. My friends had raved about the Romanesque arches at Mission San Juan Capistrano, ten miles south of downtown, so, bike in tow, I decided to start there. The grounds were so peaceful I could hear the wind whistling through the church’s bell tower. After a quick peek inside the tiny sanctuary, I was ready to ride. Naturally, there was no hint of the trail, but a helpful ranger told me to take a left at the mission entrance and cross the Ashley Road bridge, where I’d find the elusive path running along the western edge of the river. I turned left (go right and you’ll soon bump into a blockade of road and trail construction) and found myself on a wide paved track sandwiched between the river and the Acequia de Espada, a section of the mission system’s fifteen-mile-long network of irrigation ditches that is still in use today. Just past the Piedras bridge, a short trail spur led me to the Espada Aqueduct, whose stone arches have spanned Six Mile Creek for more than 250 years. After a two-mile ride, I came to Mission Espada. Despite the encroaching neighborhood and the traffic noise from the nearby freeway, I could still imagine what it must have been like when it was a far-flung outpost, vulnerable to attack.

After admiring the church’s Moorish doorway and the seven brick arches of the Convento, still home to Franciscan friars, I started back. Except for one fisherman, egrets and herons, and the occasional small plane that buzzed me as it landed at nearby Stinson Municipal Airport, I was alone with the San Antonio River and the wind-whipped fields. It was hypnotically peaceful. And as I rolled along it dawned on me that by embracing the obvious, I had stumbled—with a little effort—on that something travel writers prize: a real discovery I could honestly rave about.

The Essentials

Hotel Valencia Riverwalk, 150 E. Houston, 210-227-9700, 866-842-0100, hotelvalencia.com. Doubles from $149 to $279, suites $279 to $529 (be sure to check the hotel’s Web site for package deals).

Mission San Juan Capistrano, 9101 Graf, at Ashley, 210-534-0749, nps.gov/saan.

San Antonio Visitor Information Center, 317 Alamo Plaza, 210-207-6700, 800-ALAMO-07, sanantoniovisit.com.

University of the Incarnate Word, 4301 Broadway, at Hildebrand; the Blue Hole is at the northern end of the creek that runs through the campus.