Demi Moore is revealed to be a villainess when she shoots all three of the
Angels on top of this observatory. Fortunately, they survive (due to body
armor) but are drenched by sprinklers as they walk across the lawn.
Then, as they're heading for their car, their car explodes!

Those scenes were shot at the Griffith Park Observatory, located atop
a peak in Griffith Park, at 2800 East Observatory Road.

Madison Lee's (Demi Moore's) lair, was actually the inside of L.A.'s Union Station,
located at 800 N. Alameda Street, in downtown Los Angeles.
They used the train station's former ticket area and turned it into the huge, glitzy space
you see in the film. Union Station, built in 1939, has been seen in dozens of movies,
including 2000's "Pearl Harbor" and the movie titled "Union Station".

Above, we see Hollywood Boulevard, looking east from Orange Drive,
with the El Capitan Theatre to the right, and Grauman's Chinese Theatre to the left.

Below, we see our villain, Seamus O'Grady, standing on the star of Fred Astaire
on the Hollywood Walk of Fame. Fred's real star is actually located just a
block east of Grauman's, at 6756 Hollywood Blvd.

As part of this scavenger hunt, the crooks are told to "find a man with a map".
This scene (where they get the map) was shot in the lobby of the
Guinness World of Records Museum at 6764 Hollywood Blvd. in Hollywood.

(The museum is also seen in the recent film "Hollywood Homicide".)

Just a few blocks to the east on Hollywood Blvd., the scavenger hunt
continues, as the O'Grady gang enters a restaurant, give a suitcase to a
man in a booth, and get a matchbook in return.

That restaurant is Musso & Frank Grill, the oldest restaurant in Hollywood
(since 1919), located at 6667 Hollywood Boulevard.