Tech headquarters are attracting more these days than just millennial talent. Tourists and other curious visitors are increasingly interested in such places as Google's Googleplex, Apple Park and Salesforce Tower, all in northern California — at least in as much as they are open to the public.

Both these buildings and the tech lifestyle reflected in their amenities are fascinating to outsiders, CNBC reports. 

"Silicon Valley is the birthplace of these things. A lot of visitors from around the world want to feel closer to that and experience it firsthand," Silicon Valley Innovation Center's James March told CNBC. His organization oversees tours, education programs and conferences about technology.

A sample tour offered by the Silicon Valley Innovation Center offers a day of visiting tech hubs: Stanford University's campus, Googleplex, the Intel Museum, Apple Park and a test drive of a Tesla.

Not everything is open to casual visitors. Googleplex, for instance, allows visitors to wander around its 12-acre grounds, but not its buildings, unless they are escorted by a Google employee.

Even so, the grounds offer sights unique to Google, such as a life-size Tyrannosaurs Rex skeleton (supposedly to remind Google workers not to let the company become a dinosaur), an assortment of stone busts of celebrities and scientists, cartoon figures depicting Android operating systems and the multi-hued bicycles that Google workers use.

Apple Park, though sporting a recently completed 2.8M SF, 1-mile in circumference "spaceship" campus in Cupertino, is even less open to visitors, though the Apple Park visitors center across the street is a combination of an Apple Store, a café and a shrine to all things Apple, Business Insider reports.

"The problem with opening up the main facility for tours is we have so much confidential stuff around," CEO Tim Cook told BI.

By contrast, a bit more of Salesforce Tower, now the tallest building in San Francisco, will soon be open to visitors. Namely, the observation deck on the top (61st) floor of the building. 

Salesforce CEO Marc Benioff made a point in a recent tweet that the space would indeed be public.

The top of Salesforce Tower (the Ohana Floor) is now open.  No offices— just seating to enjoy the amazing views. Soon the public will be invited up free of charge. This is a powerful space to be shared/enjoyed by everyone in our city. Thank you to everyone who made this possible. pic.twitter.com/XdLnGXvuwi

— Marc Benioff (@Benioff) September 24, 2018

“We sort of think of this as the world’s best living room," Salesforce Global Real Estate's Elizabeth Pinkham told KPIX. "You are up here in the sky in the tallest building west of Chicago.”