Move over, Alcatraz; clear some way, cable cars; and back off, Mickey: Silicon Valley is giving San Francisco and other Golden State attractions a run for their money when it comes to drawing hordes of tourists.

Because for some tourists, taking a selfie in front of Facebook is all part of the vacation plan.

“We are all the way from India,” said Pavi Rajkumar, with family members at Facebook’s “thumbs-up” sign outside its Menlo Park headquarters on a recent morning. Alongside Rajkumar was her nephew Shriman Sendhil, who spends two to three hours a day on the social network and claims 1,000 Facebook friends. “This is the only thing that woke him up,” Rajkumar said of the visit to the company. “Disneyland didn’t work.”

Quietly but indubitably, tech tourism has become a thing. Hundreds of people a day visit the Facebook sign and Google’s Android sculpture garden in Mountain View, with many stopping at other tech giants as well, snapping photos and shooting video. And they don’t even get to go inside.

“What you’re seeing are people on a pilgrimage,” said Stanford communications professor Fred Turner, who regularly drives past Facebook and ponders the selfie-seeking travelers. Most technology tourism is of the do-it-yourself variety, but several companies offer customized tours.

Turner compared the new breed of tourists to pilgrims who traveled to the Holy Land in the Middle Ages to visit churches engaged in large-scale colonialism. “We now see pilgrimages to firms that in ways both good and bad are colonizing our everyday lives,” Turner said. “Folks are looking for a physical place behind the kind of dematerialized experience that they have online.”

A visit to Google’s Android garden in Mountain View presents a physical place, and more: Here, tourists walk among super-sized representations of the operating system’s mascots, including a hulking doughnut, immense cupcake and giant ice-cream sandwich, representing the 11 Android iterations.

“We use Google every day, every hour, so we wanted to visit it,” said Daniel Rezende, 34, an electrical engineer from Brazil on vacation with his wife, Monica, a 37-year-old dentist. “It’s an important place.”

Turner’s pilgrimage theory also seems to explain why Canadians Vicky Hsu and Philip Huang were at the Facebook sign with their baby and a selfie stick, about 1,000 miles from their Vancouver home. “We use (Facebook) every day,” said Hsu, 30, a banker. Huang, a 37-year-old airport shop manager, gestured toward Facebook’s sprawling campus and said, as might be predicted, “It’s pretty cool, eh?” They planned to drop in at Google next.

Mostly, tech tourists are not focused on a single company. They hopscotch from firm to firm.

“We just came from Oracle, then we go to HP, Google; we’re going to do Tesla, Intel, eBay and Yahoo. And Apple, I forgot Apple,” said Ray Santiago, of San Francisco, escorting his friend Eiji Matsumoto, from Tokyo, on a do-it-yourself tour that brought them to the Facebook sign. Matsumoto owns a Japanese company that designs websites.

“That’s why I like to see the high-tech companies,” said Matsumoto, 46. “Everything is huge, just huge. One company is like one city in Japan.”

For the Rezendes, of Brazil, watching Googlers pedal the company’s famous multicolored employee bikes around the campus highlighted a difference between job requirements at Google and those in Brazil. “Usually we work on just one duty and don’t move from building to building,” Daniel Rezende said, before he and Monica headed off to visit Apple’s headquarters in Cupertino.

It’s a short walk from the sculptures to Google’s merchandise shop, where a branded sweatshirt costs around $20, a Google lollipop will set you back less than $3, and the most popular purchases among the 300 to 500 people who visit daily are, according to a staffer, Android figurines for $8 to $15 and Google T-shirts for $15.

The notoriously secretive Silicon Valley tech giants offer no public tours of their facilities but generally allow limited public access. Naturally, some visitors push the envelope. “You need to know a staff member to get a tour,” an Australian visitor to Google noted on TripAdvisor in March. As a consolation, the Australian suggested an unauthorized escapade frowned upon by company security. “Can ride a Google bike around the outside of the campus if wanted though,” the visitor wrote.

Like Google, Facebook and Apple, Tesla has a branded-merchandise shop at its Palo Alto headquarters. Visitors are prohibited from exploring beyond the lobby, where the shop is located. “They come and try to take pictures of the cars,” said a security guard posted in a rear parking lot. “We kick ’em out. That’s why we’re here.”

Some tourists’ expectations go unmet. “It was nice to walk between the buildings, take some pictures and see the employees enjoy their lunch break,” a visitor to Google’s campus posted on a Google Plus thread about Silicon Valley tourism, before griping that Google provided no bathroom access. “We were redirected to a nearby public park,” the traveler sniffed. A TripAdvisor user from London recalled a disappointing incident from a visit to Google. “We got told not to use the Google bikes as they are for employees only, which was a bit of a shame,” the traveler complained.

At one of the handful of companies offering Silicon Valley tours, the trip to see the tech icons has been the most popular of its 14 Bay Area tour options for the past year.

“The selfies are the main thing,” said Tours By Locals guide Caesar Cypriano, 55. “They do all their postings, and then people on the other side of the globe go, ‘Wow, I wish I were there!'”

Contact Ethan Baron at 408-920-5011 or follow him at Twitter.com/ethanbaron.