Sixteen years after it was first eyed as a prime location for the then-nascent Wegmans supermarket chain, a onetime golf course near King of Prussia Mall opened to the public this week as home to the region's seventh Wegmans, a megastore whose customers share a cultlike devotion.

The parking lot at The Village at Valley Forge was jam-packed Monday, much as it had been a day earlier when the store opened its doors, as the curious and the ravenous motored up in large numbers to the 123,000-square-foot supermarket, visible from Route 422 and a stone's throw from the East Coast's largest shopping mall.

Some 600 employees landed jobs as a result of the Rochester, N.Y.-based chain's decision to open in the highly-trafficked zip code that is one of the region's most densely developed retailing destinations.

Company officials were happy to celebrate the achievement, given that they had first expressed interest in placing a supermarket on that site in 1996. Assembling and developing the parcel had taken many more years than originally imagined by the late Wegmans family patriarch Bob Wegman. The company had not yet built a single store in Southeastern Pennsylvania when they set their sites on the King of Prussia parcel, said spokeswoman Jo Natale.

"It was a long, apparently arduous process for the developer," Natale said, and it was not until 2010 that Wegmans signed a lease for the project. (A call to developer Dennis Maloomian at Realen Properties in Berwyn was not immediately returned Monday.)

The scene this week was of sweet victory for company officials, replete with imagery of a fruitful clientele base: Shoppers luxuriated in ravishing displays of the chain's signature prepared foods, eclectic beers, a full-service restaurant, and the additional offerings of a conventional supermarket.

"I understand the madhouse, because with Wegmans they bring everything to the table," said Bryn Mawr insulation salesman and budding beer connoisseur John Lewis, 50, who finished his lunch hour Monday inspecting the new store's selection of microbrews from the region and beyond.

Though already a customer at the Wegmans that opened a few years ago in Malvern, Lewis had been eager to use the occasion of work at his nearby Valley Forge job to see what beers were on tap and on sale by the six-pack at the new location. As he stood near a display of Goose Island Honker's Ale, he explained how he had ditched an effort to check out the store a day earlier.

Lewis said he had been heading to a nearby Wal-Mart and thought he would swing by the new megastore before heading home. The Wegmans parking lot, however, was jammed with cars. It was so packed, police were directing traffic.

About 15,000 people turned out on Day One, said store manager Kevin Lang, and an estimated 5,000 more had swung through as of midday Monday.

The appeal from a customer's standpoint, said Lewis, was clear.

"They bring a vast selection of very desired items for an assortment of different customers," he said, articulating precisely the essence of a business model that has turned Wegmans into the kind of titan whose arrival in any community is downright magnetic.

The King of Prussia store is the only one opening in the region this year, in accordance with a companywide philosophy of slow-but-sure development across the Northeast and Mid-Atlantic. Wegmans opens no more than three stores a year, if that. A store planned for a site at Montgomery Mall is tentatively scheduled to open in 2013, but no others have been announced.

Its first store in the Pennsylvania suburbs of Philadelphia opened in 2003 in Downingtown, followed by one in Warrington in 2006, in Collegeville in 2009, and Malvern a year later.

All of those sites were chosen years after Wegmans family officials had latched their hopes on securing a lease in King of Prussia, and protracted efforts to make the property developable ensued, Natale said.

The nearest store in Collegeville is a short drive up Route 422, which is a strikingly short distance between stores, given the chains footprint elsewhere in the region. Its two only stores in South Jersey, for instance, are in Cherry Hill and Mt. Laurel.

Natale said the company is convinced that "in the Malvern, Collegeville, King of Prussia triangle, there are enough people living in those areas or traveling in those areas or working in those areas to make all three stores very successful."

Contact staff writer Maria Panaritis at 215-854-2431 or or on Twitter @panaritism.