The historic Newberry Library is hosting its annual book fair this weekend, and it's not to be missed. More than 200,000 used books will be up for sale—snag your favorite reads before someone else does. (The Newberry Library, 60 W Walton St, noon. Free)
For those not heading to Lollapalooza, there's plenty of music happening elsewhere in the city. Head to Pilsen for Fiesta del Sol, one of the largest Latino festivals in the Midwest—complete with rides, music, art and tons of Mexican food. (Cermak Rd and Loomis St, 1400 W Cermak Rd, 5pm. Free)
3. Save the world from a nuclear war
The popular, interactive Cold War room escape The Last Defender has been extended at the Chopin Theatre through the end of the month. Grab some friends and do your best to save planet Earth as we know it. (Chopin Theatre, 1543 W Division St, 7pm. $40)