And Cassa, wasn't there an episode filmed in the Hollywood Bowl?

I seem to vaguely remember that Paul....but right now the name of the episode escapes me!!

Oops, I forgot "Etude in Black" which
was filmed in the Hollywood Bowl.
How could I forget? Thanks, Paul!

All good suggestions. And don't forget (assuming that it's possible to drive close enough to see it): the famous "Stahl House", featured in multiple "Columbo" episodes including "Prescription: Murder," "Murder By The Book" and "The Most Cricial Game". See:

http://www.columbo-site.freeuk.com/flashback.htm

If you're willing to drive out of town, a memorable stop would be the Palm Springs Aerial Tramway, from "Short Fuse":

http://www.pstramway.com/

And by all means, no Columbo fan's visit to LA is complete without a stop at Barney's Beanery!!!... portrayed literally in "Ransom For A Dead Man" and in fictional form in several later episodes. See:

http://www.columbo-site.freeuk.com/chili.htm