The Colorado History Museum, the Denver Zoo, the Denver Botanic Gardens and the Museum of Contemporary Art in Denver are all letting people come and visit without having to pay.

Denver Mayor John Hickenlooper kicked off the free activities at 9:45 a.m. on Saturday at the Colorado History Museum. The museum has a new exhibit about Denver's past 150 years.

There is also:

- A free screening of The Polar Express at the Ellie Caulkins Opera House at 11 a.m. with the donation of a toy or a pajama set.

- A free performance of "Girls Only" at the Garner Galleria Theatre at 2 p.m.

- A cake to celebrate the birthday at both the Zoo and the Botanic Gardens.

- Performances by Cherry Creek Dance with 150 kicks along Third Avenue.

- Gift cards in Cherry Creek North to the first 150 guests on the parking deck at 288 Milwaukee Street.

For more information, visit www.denver150.com or www.denverartsweek.com.

For more weekend events, visit http://denver.metromix.com/home/roundup/weekend-shenanigans/784558/content.