Denver is full of buildings brimming with unique design details and fascinating histories that are unknown to many who call this city home. Fourteen years ago, the Denver Architectural Foundation (DAF) set out to change that with Doors Open Denver, a weekend-long event that gives the public the opportunity to wander freely behind iconic Denver buildings’ often-closed doors.

This year’s mix of free and ticketed events includes self-guided tours of more than 70 sites, plus expert-led excursions, including a behind-the-scenes tour of Denver’s Central Library, a trip back in time to Five Points’ heyday, and a walking tour of Curtis Park, Denver’s oldest residential neighborhood.

We asked the DAF’s executive director, Pauline Herrera Serianni, how to get the most out of this year’s event. Here, her tips for where to go and what to see:

Plan ahead. With so many buildings open to the public this year, it’s best not to wing it. “Definitely go online and choose your favorites first,” Herrera Serianni suggests. “There are 21 brand-new sites this year, so we definitely recommend you plan your weekend.” Most sites are open from 10 a.m. to 4 p.m. each day, but Sunday hours may vary, especially for church buildings.

While you’re online, check out the $10 ticketed Insider Tours. Many of these expert-led tours will sell out long before the event, but DAF members can purchase tickets early, so considering joining online to get first dibs.

Hit the highlights. Most of Denver’s historic neighborhoods will be represented this year, with a focus on Five Points and Highland. In Five Points, don’t miss the legendary Rossonian Hotel and jazz bar. After sitting empty for years, the iconic building—which, in the 1930s and 1940s, was the most important stop between Kansas City and Los Angeles for jazz musicians—is finally slated for a redevelopment that will honor its storied past (the spot is slated to be revived as a hotel, restaurant, and jazz bar, backed by former Denver Nuggets player Chauncey Billups). For this weekend only, developer Palisade Partners will open the doors to the historic site to host cultural activities including historical re-enactments and jazz and dance performances.

Herrera Serianni’s Highland pick is the Highlands Church and the Holiday Theater. Once known as the Egyptian Theater, this Art Deco building has been closed to the public for years—until it was reincarnated as a church in 2013. “For anyone who loves the Mayan Theater, go check this one out,” Herrera Serianni says. “It will absolutely blow you away.”

Bring the kids. From fire station tours to free dance classes at Cleo Parker Robinson Dance, many events are designed with kids and families in mind. Pair a visit to a gorgeous church with a mini organ recital, or stop by the historic Sugar Building in LoDo and let the kids experience a lift in a real birdcage elevator—one of the oldest of its kind. Another fun option: Work together on a neighborhood-wide scavenger hunt, earning unique stamps designed by Denver artists at various arts and culture activities, presented in partnership with the Bonfils-Stanton Foundation and various neighborhood sites.

If you go: Doors Open Denver takes places throughout the city September 22–23. Hours for free, self-guided tours are 10 a.m. to 4 p.m., with some exceptions. Ticketed tours are also available for $10 each.