In the recession, ultraluxury retreats are getting soaked.

It took 20 years and undisclosed millions of dollars to build the Resort at Pelican Hill on the California coast just south of Los Angeles. The centerpiece of the complex is the "Coliseum"—a two-story, semicircular, epic-scale colonnade enveloping the world's largest circular pool, decorated with $1 million-plus hand-cut custom glass tiles. A Tom Fazio golf course adorns the hills overlooking the ocean. The rooms aren't merely rooms: They're bungalow-suites and villas, arranged to resemble a Tuscan village. Gracious, superbly trained staff wait discreetly to attend to the wishes and caprices of guests. As a sometime travel writer, I have been lucky enough to stay at dozens of the world's large luxury destination hotels and spas. This one is as good as it gets.

And yet, on a recent visit, my husband and I had the pool, the Zen-like spa, and any number of Palladian porticoes to ourselves. Aside from a clutch of day visitors and a small group of business travelers who showed up that evening, we were alone. The staff brightened up considerably when they caught sight of us, perhaps relieved just to have someone to talk to. As I watched the sun set over the forlorn colonnade around what now looked like the world's largest reflecting pool, I wondered if I was witnessing the end of an era of human civilization. Is the age of the ultraluxury spa resort finished? Or is this just a temporary eclipse?

The hospitality industry as a whole is reeling from the recession. PKF Consulting, a Georgia-based firm of industry specialists focusing on hospitality and tourism, titles its March report on the industry "How Much Do You Stand To Lose in 2009?" The firm reported a 5.3 percent decline in occupancy, coupled with a 2.7 percent fall in room rates, leading to a 14 percent decline in net operating income for the average U.S. hotel from 2008-09. But the luxury-destination end of the business—where nightly accommodation charges can start at $700, as at Pelican Hill, and guests might spend equivalent sums on pampering, sports activities, and haute cuisine—seems to be taking a much harder hit.

It is difficult to get a handle on precise numbers in such a secretive industry, but the steady drip of closures and bankruptcies in the sector cannot be good news. MGM Mirage's City Center Project, an $8.6 billion Las Vegas development that included a 4,000-room resort and two smaller hotels-all with spas-is on the brink. West Virginia's historic Greenbrier Resort—whose motto happens to be "Defining Luxury Since 1778"—filed for bankruptcy in March. In Atlantic City, N.J., the Tropicana Casino and Resort is also struggling to find a buyer as its parent company, Trump Entertainment, fends off impatient creditors.

The "postponement" of many planned projects also signals just how challenging the current climate is for the resort and spa industry. Susan Harmsworth, founder and chief executive of Espa, a U.K.-based spa company that works with Peninsula, Ritz-Carlton, One & Only, and other high-end resorts around the world, reports that since October, 20 of her company's spa projects have been either canceled or postponed.

And newer projects are suffering more. The Mandarin Oriental Hotel Group has spent nearly a decade building up an image of luxury chic in the United States. On a March evening, the Mandarin Oriental Miami's fine-dining restaurant, Azul, was filled with stylish travelers from Europe, Latin America, and the East Coast, chatting over yogurt-marinated swordfish and Florida stone crab. The property still attracts large numbers of leisure travelers, thanks to its well-established cachet. But just across the bay, in full view of the diners at Azul, lies the Icon Brickell-four imposing towers dominating the skyline, built by Miami "condo king" Jorge Perez. The project includes a boutique hotel and spa. The towers were largely dark.