Open to the public for the first time ever, the Liggett Hall Gymnasium at Governor’s Island was used by the Coast Guard until their departure from the island in 1996. Here’s a fun fact: the building is as long as the Chrysler Building is tall, meaning it’s mighty big. It was designed by McKim Mead and White in 1821.

Curbed readers deemed the Cunard Building’s interiors some of the most beautiful in New York City, and during OHNY weekend, you can check them out for yourself—the lobby will be open for tours on Saturday from 10 a.m. to 2 p.m. The marble-covered building, which opened during the glory days of steamshop travel, was meant to resemble Roman baths.

The beautiful Cass Gilbert-designed Customs House building at the southern tip of Manhattan, now home to the Smithsonian’s National Museum of the American Indian, the National Archives and Records Administration, and the US Bankruptcy Court, will be open to visitors this OHNY weekend. As an added perk, the building’s rarely opened Tiffany-designed Collector’s Office will also be open for viewing.

This tiny, normally off-limits cemetery will open its doors for OHNY as part of the event’s Spaces of Respite program, which highlights spaces that “provide some serenity and respite from the chaos of the city”—something we all need right now. It’s open all day on Saturday and Sunday. The similarly-named New York City Marble Cemetery will also be open for tours from noon to 5 p.m. both days.

OHNY has included tours of this beautiful West Village library in its itinerary for years, and it remains super-popular with participants—probably because you get to explore the inner workings of the Gothic landmark, including its iconic clocktower. It’ll be open on Saturday from noon to 4 p.m.

This former Bell Labs Building in the West Village is now the country’s largest artist community, with 383 live-work spaces for artists and their families. The building’s history is enticing—it’s where the talking movie and binary computer were first demonstrated—and its architecture is equally so. The building was converted into housing with a design by Richard Meier way back in 1970. The building became a New York City landmark in 2011.

This Upper East Side campus will be open to curious visitors during OHNY, with participants able to visit its public-facing spaces, the Collaborative Research Center, and the university’s new, modular addition, which is still under construction.

You know the joke about Grant’s Tomb, but get the backstory on the memorial in Riverside Park—which was designed by architect John Duncan, and remains the largest mausoleum in the country—during tours on Sunday. Three different walks, led by National Parks Service rangers, will go in and around the Grant memorial.

If Brutalist architecture is of interest, one would be hard-pressed to skip this tour of Marcel Breuer’s contributions to the Bronx Community College, including Meister Hall, Colston Hall, Begrisch Hall, and Carl Polowczyk Hall. The buildings dating to the late 1950s and early 1960s would go on to become a cornerstone of Breuer’s aesthetic, and Begrisch Hall would even become a city landmark.

There’s a lot going on with the townhouse at 158 Clifton Place, which was renovated by Paul Castrucci Architects: it’s a timber-framed home, which was recently renovated to Passive House standards, and uses a plethora of recycled materials—namely reclaimed wood from New York state. The architects will lead tours on Saturday between 2 and 6 p.m. if you want to learn how an older home gets revamped for the future.

Annabelle Selldorf designed the SIMS Sunset Park Material Recovery Facility, which boasted a budget of $89 million and is LEED certified, in part because 98 percent of the complex is made out of recycled steel. Inside, there's an education center, classrooms, offices, a theater, and a large outdoor terrace with views to Lower Manhattan. New York Times critic Michael Kimmelman described it as "understated, well proportioned and well planned—elegant, actually, and not just for a garbage site."

Surely there’s some intersection between beer and civic nerds, right? If you’re one of the people for whom those two topics are like catnip, then you’ll want to join a tour of Staten Island’s Flagship Brewing Company, which opened in 2014 and has a huge tasting room (and tasty beers). There’ll be tours on Saturday at 2:30 and 4 p.m.