Being nebby isn’t always a good thing, but Doors Open Pittsburgh encourages it. On Saturday, the annual event will give visitors an inside look at 22 iconic, historically significant or just plain interesting structures in Downtown Pittsburgh and on the North Side. Hours are 10 a.m. to 4 p.m.; individual building hours may vary. Ten sites are new to the tour this year. Typically, the tour covers two days and features 50 to 60 buildings, but because of pandemic safety concerns, "we’re thrilled to even be able to offer 22 buildings in one day,” said Doors Open Pittsburgh founder Bonnie Baxter. "I love the list of buildings. It includes new-design buildings and old buildings re-purposed; it’s a really diverse blend.” Most of the featured buildings will be open for a self-guided experience, while others will feature a 10- to 15-minute guided tour. Ticket-holders can visit buildings in any order they desire. "Where there is a greeter present, you’ll only be going as far as the lobby and, quite frankly, in those buildings, the lobby is the real story,” Baxter said. On the river It’s a stretch to call two of the sites "buildings,” she added, but those new additions are among the most intriguing features of the tour. One is the Pittsburgh River Rescue boathouse on the Allegheny River, under the Seventh Street/Clemente Bridge on the North Shore Riverwalk, built in 2000 to replace the old one that was demolished during construction of PNC Park. The other is Rivers of Steel’s 94-foot Explorer Riverboat floating classroom, a sustainable vessel docked on the Allegheny River along the North Shore Trail by the Vietnam Veterans Memorial. Other iconic sites are PPG Place, David L. Lawrence Convention Center, Midtown Towers, Smithfield United Church of Christ and the Historic Park Building downtown, along with the circa-1888 Boggs mansion, now a bed-and-breakfast in the Northside’s Mexican War Streets. Doors Open even goes underground, into the 19th-century lagering caves carved into a North Side hillside on the present-day grounds of Penn Brewery. Look up and enjoy Baxter modeled the event on a similar tour hosted by the Chicago Architecture Foundation, for which she did advertising while living in that city. "This kind of event got its start in Europe, where about 40 countries have something like it,” she said, adding that North American cities including Toronto, Baltimore, Denver and Minneapolis also have tours. "Pittsburgh is lucky to have such a wonderful and diverse collection of buildings, and Doors Open Pittsburgh reminds us all to look up and enjoy it,” according to Pittsburgh Mayor Bill Peduto. Doors Open Pittsburgh has hosted past architectural bus tours, which are on hiatus because of the pandemic. A new series of virtual tours will launch on the website during the week of Nov. 2, with the first tour covering the local music scene. The list will be announced Oct. 19. Previous virtual tours are archived on the website. On Oct. 17, Baxter is planning two seatings of a vintage purse tea party, featuring local collector Megan Wojcik, who will talk about "the swankiest parties in Pittsburgh, speakeasy raids, fashion icons and Hollywood royalty.” Tea party tickets go on sale Oct. 5 on the website. Tickets for the Saturday building tour are $12, $10 for ages 65 and up, $5 for ages 5-17 and free to younger children. Baxter encourages buying advance tickets on the website. A limited number of tickets will be available on tour day at the event center in Market Square. Masks will be required for entry into all buildings, and entry will be managed to ensure social distancing. For information and reservations, visit doorsopenpgh.org. Shirley McMarlin is a Tribune-Review staff writer. You can contact Shirley at 724-836-5750, smcmarlin@triblive.com or via Twitter .