Open House Chicago lets you crash Chicago's best

Over 100 significant buildings and homes in 30 different neighborhoods will open their doors this weekend for the annual Open House Chicago.

Why it matters: The festival gives Chicagoans a chance to peek behind the curtain at some of the best architecture and design in the city. It's one of the largest architectural festivals in the world.

Three spaces to check out:

Sky-Line Club: The private club is actually an old English ale house that was brought here piece by piece nearly 100 years ago. It lives high atop the Old Republic Building at 307 N. Michigan Avenue, just south of the Chicago river.

• The original paintings and furnishings are still on display and you can see both the inside and the views of downtown from the balcony.

Eris Brewing and Cider House: Who doesn't want to see a new cider house inside the Masonic temple building in Old Irving Park?

• The Masons worked out of this building from 1911 to 1981. The brewery recently took over and renovated the first floor.
• 4240 N. Irving Park Road.

The Wheeler Mansion: Now this is the good stuff! The South Loop mansion is the last of it's kind on Calumet Avenue. Built in 1870, it predates the Chicago Fire. The classic Chicago mansion fell into disrepair and was bought for just $10,000 in 1997.

• The mansion is now a boutique hotel.
• 2020 S. Calumet Ave.

If you go: The Chicago Department of Health says you must wear a mask at all times while touring the indoor spaces.