SAN FRANCISCO, Calif. (KRON) — Robbin Williams Meadow in Golden Gate Park, also known as “Hippie Hill,” is going to look and feel different this 4/20 from past cannabis celebrations.

The hill has been a longtime mecca for free-spirited hippies and cannabis enthusiasts to gather every April 20.

This year, festivities at Hippie Hill will be “organized,” “coordinated,” and “sponsored,” to ensure they do not become “problematic,” San Francisco Mayor London Breed said bluntly.

At a news conference held Monday, Breed smiled as she told reporters, “We are here to talk about one of our favorite times of the year, 4/20.”

Breed said, “In the past, we have not been smiling about 4/20. It experienced a number of challenges. Fortunately from the past, we’ve learned how to adapt, how to adjust, and how to make the event a more enjoyable event, not just for the people who come here from all over the Bay Area to attend, but for the people who live in the surrounding community.”

City officials anticipate up to 20,000 people flocking to Hippie Hill Wednesday.

“It’s been a tough two years. And here we are back together again having great events. The Giants and their home opening season …. the Warriors played a playoff game in San Francisco, and the Cherry Blossom Festival was packed with visitors. People are coming back to San Francisco. We are able to have major events and enjoy our lives once again,” Breed said.

“And of course 4/20 is no different. This event, at one point unsanctioned event, was occurring whether we wanted it to or not,” the mayor admitted.

It’s been five years since recreational marijuana became legal in California for anyone 21 and older.

A strict 21-and-older age requirement will be enforced on the hill, Breed said.

“This event will have food, entertainment … and for the first time, because of changes to local and state laws, there will be on-site (legal) cannabis sales,” Breed said.

Regulated and tested cannabis products will be available for purchase at the event. The new development also brings new restrictions — nobody under 21 will be allowed to enter the celebration area, which will be surrounded by two fences. Event staff will check identification and bags. Entry begins at 10 a.m. for the festival, which starts at noon and ends at 5 p.m.

“If you are under the age of 21, you will be turned away,” the major said.

San Francisco Police Department officers and other law enforcement agencies will be monitoring the area to ensure that the event is enjoyable and safe for everyone.

“This year marks an important moment in the history of 420 at Hippie Hill,” said Nikesh Patel, director of the San Francisco Office of Cannabis.

Patel said, “For the first time, regulated cannabis will be available for sale and consumption at this year’s event. This novel opportunity showcases the strength of San Francisco’s vibrant cannabis community and brings new requirements to help create a safe, clean, and enjoyable experience for everyone who attends.”

Bus shuttle services to BART stations will be provided to help prevent cannabis users from driving while under the influence of marijuana.