Doors Open Denver celebrates the city's architecture

Denver's most notable buildings will open to the public starting today as part of the annual Doors Open Denver event.

Why it matters: The four-day event offers a rare insider's look at the buildings that define the city's architecture.

State of play: This year's event, sponsored by the Denver Architecture Foundation, includes tours of the Brown Palace, the University Club of Denver, a revamped 16th Street and the sea lion habitat at the Denver Zoo.

• Other ticketed events include a toast to the life and work of Dana Crawford at the Harry C. James Residence and an evening on the rooftop of One River North, the eye-catching new building in the RiNo arts district.

Between the lines: Many of the events are ticketed, but free tours of the Boettcher Mansion, Castle Marne and the Denver Woman's Press Club are available.

What they're saying: "Whether you're a lifelong resident or new to Denver, this festival will deepen your love for the city's architecture and natural beauty," Meg Touborg, president and CEO of Denver Architecture Foundation, said in a statement.