Location of Tesla School graduation ceremony in episode 1x12 “Once in a Lifetime”.
Location of Allison and Nathan's wedding in episode 3x04 “I Do Over”.
Spa that experiences some instant freezing in episode 2x03 “Unpredictable”.
Oliver walks through the grounds with Diggle discussing the strangeness of reality when they are attacked by Deathstroke in episode 5x08 “Invasion!”.
Source: pursuit23 — Twitter
Ray is taken to the park by The Smell and challenged to steal one of the Queen's corgis for a prank. Later, he returns to the park to report to Mick and show off his sweet tat in episode 4x03 “Dancing Queen”.
Nate and Gary go hunting a magical anomaly in the distant past but are forced to return early by a saber-toothed tiger in episode 4x03 “Dancing Queen”.
The pod lands outside the strange city and Kara heads into town and grabs a disguise with her companion in episode 3x20 “Dark Side of the Moon”. Kara is talking to some locals in the market when a construction crane collapses and later she goes to dinner with her old childhood friend Thara in episode 3x21 “Not Kansas”.