Port Mann Power Station as Portal Warehouse (exterior)
The Resistance is constructing a portal to another world when they are attacked.
“Crisis on Earth-X, Part 1” Filming Locations
All of the heroes assemble for the wedding of Iris & Barry.
Supergirl episode “Crisis on Earth-X, Part 1” was filmed in Vancouver, New Westminster, & Surrey in Canada.
1133 Melville Street as Fighting Ninjas
Oliver gets a call from Felicity about the wedding while he is fighting a group of ninjas.
Alley (south of Bute, west of Pender) as National City Alley
Kara fights a dominator and chats with Alex.
Sugar Nail Bar as Nail Salon
The girls chat while getting ready for the wedding.
Source: What's Filming — Twitter
St. Andrew's-Wesley United Church as St. Paul Lutheran Church
Kara waits for Alex outside the venue and learns about her sister's night with Sara.
1133 Melville Street as Rooftop
The evil versions of Kara, Oliver, and Wells assemble on a rooftop after their attempt to kill the heroes fails.