After inventing geometry and physics, Greeks invented history—primarily as a way to document their many inventions. Take a stroll through history with today’s Groupon: for $20, you get a Summer Fun Day Pass, which includes admission, a carousel ride, and a planetarium show for up to five people at the Grand Rapids Public Museum (up to a $60 value).

The Grand Rapids Public Museum deposits nuggets of locally-minded knowledge into waiting brains with attention-grabbing exhibits and interactive opportunities. Visitors stroll the streets of a 3/4-size replica of 1890s Grand Rapids, drinking in sights at the antique opera house, guzzling an imaginary phosphate at Rudell Drug Store, or haranguing costumed interpreters about the impracticality of the new horseless-carriage fad during a rest at the barrel factory. Immerse kids in the environments of Michigan birds and other wildlife with the help of the Habitats exhibit’s interactive sights and sounds. Other denizens of the museum's three floors of exhibits include a 76-foot whale skeleton and ancient Egyptian mummies. A Summer Fun Day Pass grants each guest a ride atop the carved wooden horses and menagerie animals who roam the 1928 Spillman Carousel, which moves to the music of a Wurlitzer band organ, as well as a planetarium show, when available, where watchers can brush up on celestial know-how. Summer Fun events run from June 20 through Sept. 2. Penny presses, "I Spy" games, and "Storytime with The Mighty Wurlitzer" engage the minds of little ones, while the food offerings at the second-floor cafe engage the stomachs of all.