The Going Out Guide is hosting a happy hour tomorrow from 5 to 9 p.m. at Suburbia, the pop-up bar outside Union Market. Here are five reasons you should join us for this free event. (Hmm, maybe that makes six.)

Suburbia The Suburbia pop-up bar outside Union Market is inside a vintage 1960s Airstream trailer.  (Photo by Fritz Hahn/The Post.)

Cheap frozen drinks
The bar, set up inside a vintage Airstream trailer, pours frozen cocktails made with fresh fruit and decent liquor – nothing from concentrated mixes. For our happy hour, they're marking the cocktails down to $5 from the usual $8. Special for the night is a cocktail made with watermelon, rum and mint, and crafted by guest bartender Patrick Owens of the Tabard Inn. Other choices include a frozen gin rickey, the blackberry margarita, the Grappling Grape (gin, grapes and rosemary) and, my favorite, the pina colada, which has chunks of real pineapple floating in the tequila slush.

Cheap and/or Good Beer
Yes, you can get cheap tallboys of Coors or PBR -- in custom koozies, no less – for $3 to $5 at our happy hour. But there will also be four drafts from Falls Church's Mad Fox brewery for those who enjoy the finer things in life.

Good food
Chef Peter Smith, formerly of PS7's restaurant, will be manning the grill with three different kinds of homemade sausage. If you want tacos, empanadas, cupcakes, knishes or even oysters, there are plenty of merchants inside Union Market.

Lawn games
The grassy swath of Suburbia outside Union Market is home to multiple corn hole sets and a badminton net. They're free to play.

A bit of Suburbia
If you haven't made it to Suburbia yet, time is running out. Next weekend is the final one before the Airstream heads down to New Orleans for the annual Tales of the Cocktail convention. Nothing has been decided about its next destination, so enjoy sitting in an Adirondack chair with your feet in the grass while you can.