Where to indulge your inner geek in Silicon Valley

Facebook's "Like" sign, which sits at the entrance to the social media giant's campus in Menlo Park, California, is about the only thing that visitors can see and photograph at Facebook without knowing an employee.

Chada knew that for her sister visiting from Singapore, like hundreds of other tourists who come here daily, just posing for a picture and posting it on Facebook for their friends to see and "like," would be worth the stop.

"This is a little Eiffel Tower of Silicon Valley," Chada said. "The last time we were here, there was a line."

A pilgrimage to the tech giants

From the Facebook billboard to the Google Android sculptures to Apple's One Infinite Loop sign, social media addicts, engineers, and tech geeks from around the world make daily pilgrimages to see, touch and interact with the tech brands changing life as we know it.

The world's first high-technology region is a suburban world of office parks that are mostly closed to the public, which comes as a surprise to some travelers.

At least nine Bay Area tour groups offer Silicon Valley tours, with the caveat that few offer any inside access. Still, a friendly tour guide will give you the history of these famous tech companies and the area.

"At the pinnacle of car culture, tourists wanted to go to Detroit. It's natural that in the Information Age, tourists would come to Silicon Valley," said historian Randall Stross, a Silicon Valley-based author and business professor at San Jose State University.

"I don't understand the appeal of taking a selfie in front of a sign found on the campus of one of the iconic Silicon Valley companies," said Stross. "But I do understand the impulse to mark the visit in some way, and no better access is offered by the companies."

That may be changing. Apple recently let reporters inside its new visitor center, a floor-to-ceiling glass building that will have a cafe, store and viewing pavilion overlooking the new spaceship campus. It's scheduled to open later this fall.

If you're traveling on your own, here's where you can get a taste of "The Valley"'s tech companies and the tech-empowered local businesses capitalizing on the tech theme.

The Tech Giants: Facebook

Like Chada's sister, fans of the social network get a kick out of posing in front of the "Like" sign at the company's headquarters.

Look on the back of the sign to see the old sign for Sun Microsystems, the once thriving computer systems company that used to own the campus. http://time.com/facebook-world-plan/

There's no visitors center, public tours or gift shop. But during the warmer months, Facebook holds several community festivals and a farmer's market on the main parking lot that are free to the public. And there are plans in five years to have an entire Facebook village with a grocery store, pharmacy, houses and offices -- which will all be open to the public.

Facebook, One Hacker Way, Menlo Park, CA 94025

The Tech Giants: Google

At the Mountain View headquarters of Google and its parent company, Alphabet Inc., sadly, you won't be able to see the free laundry rooms, swimming pools or cafeterias without an employee contact.

But visitors are encouraged to photograph the Android sculpture garden, with more than a dozen whimsical homages to the Google Android mobile operating system names (cupcake, jelly bean, ice cream sandwich). Though Google's visitor center is limited to guests of employees, all are welcome at the Google store nearby, where company t-shirts, stuffed Android toys and other swag are for sale.

Google Android Lawn Statues and company store: 1981 Landings Drive, Mountain View, CA 94043

The Tech Giants: Apple

Across the street from Apple Park, the company's new 2.8-million-square-foot campus, the company has built a floor-to-ceiling glass visitor center scheduled to open in late 2017. The building features an Apple store with exclusive merchandise, a café, outdoor seating area and rooftop deck from which the public can get a good look at the new "spaceship" building. There's also a model of the new campus that visitors can explore with an augmented reality app.

For now, visitors to the current headquarters in Cupertino can make do with a photo in front of the One Infinite Loop sign and a visit to the campus Apple store, which carries exclusive collectibles to make your Apple fan friends jealous, like retro t-shirts with the rainbow Apple logo from the original Macintosh.

Apple Visitor Center, 19111 Pruneridge Avenue, Cupertino, CA 95104, opening late 2017.

Where the robots are at your service

Bay Area innovators are clearly planning for the day robots take over. Case in point: In Silicon Valley, Mountain View-based Zume Pizza will deliver you a pizza made primarily by robots: One flattens the dough, a second squirts on the sauce, another spreads the sauce and a fourth slides it in the oven. (A human takes it out of the oven.) Once assembled and partially cooked, the pizzas are loaded onto delivery trucks outfitted with ovens to minimize delivery time. As for their taste, the reviews are pretty good so far. Zume gets 3.5 out of 5 stars on Yelp, compared with 2 stars for the local Domino's.

Calafia Cafe, the Palo Alto restaurant begun by former Google Executive Chef Charlie Ayers, has Sally, a robot who can mix up a salad in less than a minute.

If you stay at the Aloft Cupertino or Aloft Silicon Valley, you might run into "Botlr," a robot butler that resembles R2-D2 and is said to have the humor of Rosie from "The Jetsons." The robot splits its time between the two properties most of the year, can deliver guest amenities and move linens between the laundry to guest rooms. But don't expect it to talk with you; it communicates through a touch screen interface. Call ahead to make sure Botlr is scheduled to be at the hotel during your stay.

Zume Pizza: Available for delivery in Mountain View and some surrounding areas, Sunday-Thursday 11 a.m.-10 p.m., Saturday and Sunday 11 a.m. -- 11 p.m; +1 844 330-5590.

Calafia Cafe, Town & Country Shopping Plaza, 855 El Camino Real #130, Palo Alto, CA 94301; +1 650 322-9200.

Aloft Cupertino, 10165 North De Anza Boulevard, Cupertino, CA 95014; +1 408 766-7000

Aloft Silicon Valley: 8200 Gateway Blvd, Newark, CA 94560 +1 510 494-8800

Try the gadgets you hear about

IngDan is a China-based company that helps Internet-of-Things startups get their products to market. At the company's IngDan Silicon Valley Experience Center, the public can see and try new Web-connected toys, appliances and gadgets, like some of a dancing robot playmate or a 3-D printer pancake maker. Any startup can apply to have their gadget on display.

The IngDan Silicon Valley Experience Center, 4500 Great America Parkway, Suite 250 Santa Clara, CA 95054, Monday to Friday, 9am - 6pm; +1 415 308-1235. Admission: Free.

Intel: Where history was made

The world's largest silicon chip maker might be the only Silicon Valley company that has its own public mini-museum. Located at Intel's Santa Clara headquarters, the free museum takes you through the micro-miniature world of computer chips.

Visitors can see demonstrations of how the chips are made and kids can try on the suits worn by workers in the ultra-clean factories. The gift shop carries branded clothing, jewelry and other souvenirs.

Intel Museum, Robert Noyce Building, 2200 Mission College Boulevard, Santa Clara, CA 95054; Monday--Friday, 9 a.m. to 6 p.m.; Saturday, 10 a.m. to 5 p.m. +1 408 765-5050 (call to make sure museum is open); Admission: Free.

How the computer came to be

Just up the road from Google at the Computer History Museum, zoom through the first 2,000 years of computing from the abacus to the smartphone and get a taste of what it's like to program software. You can even sit in a Waymo (the Google spinoff) self-driving car.

Computer History Museum, 1401 North Shoreline Boulevard, Mountain View, CA 94043. Wednesday-Sunday, 10 a.m. to 5 p.m.; +1 650 810-1010; Admission: $17.50.

HP Garage

In the 1930s, Stanford University Dean of Engineering Frederick Terman encouraged students to start their own electronics companies in the area instead of taking jobs at established companies back East.

Stanford grads William R. Hewlett and David Packard were the first to take his advice, developing their first product, an audio oscillator, in this garage in 1938. Hewlett-Packard bought the property in 2000 and restored the house, garage, and shed to much the way they were in the 1930s. The garage, which sits on a quiet street in Palo Alto's Professorville district, is listed on the National Register of Historic Places.

Unfortunately, you can't get past the gate without an invitation from an HP executive, but you can read the plaque and take a picture from the sidewalk.

HP Garage, 367 Addison Avenue, Palo Alto, CA 94301. Not open to the public (garage and sign viewable from the street.)

Follow the money

If you have a couple more hours, drive along Sand Hill Road, a storied one-mile strip in Menlo Park that's home to most of the area's venture capitalists. Sip cocktails at the Rosewood Sand Hill Hotel, where you'll probably pass more Bentleys and Rolls Royces in the parking lot than you've ever seen before.

Rosewood Sand Hill Hotel, 2825 Sand Hill Rd, Menlo Park, CA 94025; +1 650 561-1500.