Four renowned DJs and The EndUp will heat up Union Square’s Winter Walk on Saturday, with an all-ages house music dance party rager that’s absolutely free to attend. We admit we were surprised this past June when the City of San Francisco handed the keys to Union Square to — of all people — the staff and DJs of the notoriously hedonistic LGBTQ bar The EndUp, for The EndUp’s 50th anniversary party in Union Square. We are even more surprised that this Saturday, city officials have decided to do this again.     View this post on Instagram A post shared by The EndUp (@endupsf) The event is called EndUp Live at Union Square’s Winter Walk, and runs from 3pm - 9pm on Saturday, December 21 at Union Square. It’s an all-ages show and free to attend, and remember that the Union Square Winter Walk does indeed have multiple outdoor cocktail booths. “FREE PARTY,” The EndUp says in their announcement. “Saturday December 21st - Union Square take over with special guest Harry Romero (NYC)! Endup live on San Francisco's Winter Walk Stage featuring a house music legend.”New York’s Harry “Choo Choo” Romero has the headlining slot (5:30 pm), and the party will also feature sets from Dean Samaras (8 pm) and resident EndUp DJs Hawthorne (4:30 pm) and  Bryan Boyce (3 pm).Not surprisingly, there will also be an afterparty at The EndUp featuring sets from Romero and Samaras.Related: The EndUp Turns 50 and They're Taking Over Union Square With a Dance Party Saturday [SFist]Image: Dean Samaras via Facebook