Oakland -- Oakland has stayed at the forefront of the cannabis legalization movement, with advocates and city government working hand in hand for more than 15 years.

Now, folks will finally get the chance to light up outside City Hall. Legally, that is.

A cannabis street fair touted as the first in the nation is set for this weekend, featuring speakers, music, booths and vendors. But perhaps the most unusual attraction will be the "215 area," a designated spot directly in front of City Hall where those with a valid medical cannabis card will be able to ingest, smoke or vaporize their pot. There will be devices to help folks make their own hash, a marijuana derivative. The open-air lounge, so to speak, is believed to be the first of its kind in the country.

The "215" in the name is a reference to Proposition 215, the 1996 state ballot measure that legalized personal use of medical marijuana.

"Patients need to take their medicine when they need to," said Kim Cue, a Berkeley resident who is chief executive of the International Cannabis & Hemp Expo, which starts Saturday at noon. "Being a patient myself, that's something that's mandatory."

In the years since voters approved Prop. 215, Oakland has increasingly found itself at the forefront of a fight to test the limits of the law. The city is believed by Oakland's elected officials and cannabis activists to be the first in the nation to license dispensaries. A battle with the federal government involving an early cannabis-buying cooperative in Oakland went to the Supreme Court in 2001 - which the dispensary lost. City voters in 2004 passed Measure Z, making possession of small amounts of pot the lowest priority for police. Underground pot clubs have been operating ever since. In 2009, Oakland voters passed a measure to tax and regulate cannabis businesses - the first such tax in the country.

The city also has an array of cannabis-related businesses, particularly in a section of downtown known as Oaksterdam. The city's pot identity is something the expo's promoters, as well as locals, want to tout.

"Oakland needs to be the tourist destination for cannabis," said Salwa Ibrahim, who handles government relations for Oaksterdam University, which trains students for the industry. "We felt like a street fair for the cannabis industry would help solidify that."

The university alone has some 2,000 students a year, more than half of whom come from out of state. The cannabis expo has been held the past two years at the Cow Palace, but a state moratorium on drug use in state facilities nixed a return, Cue said.

Oakland's two-day event will close off the area bounded by Broadway, Clay Street, 14th Street and 16th Street, including Frank Ogawa Plaza. Only adults will be allowed inside, and there will be a single point of entry, Ibrahim said. Tickets start at $20. Organizers expect at least 20,000 people.

For Richard Lee, the founder of Oaksterdam University and the owner of one of the city's four dispensaries, the street fair represents a bit of a milestone.

From a time when marijuana use was on the fringe of society just a decade ago, it's moved to the mainstream. Politicians no longer fear being associated with it.

"It shows that Oakland sees that cannabis can be taxed and regulated and incorporated into the rest of society," Lee said. "We're just one of many battlegrounds in a very big war."