What are your memories of these places. I assume they've all been shut down for awhile.
A brief description from my memories from around the year 2000 - 2002.
Masterdome
The Dome was in San Bernardino. When you entered this venue, you'd see the circular ceiling above, with a ring surrounding the main arena. It was a small place that got unbearably hot at times. The main problem with this area was the getting into the dome and outside into the smoking/air area. Just imagine driving on a one way street in SF/LA and seeing it become a two-lane disaster up ahead. Still, this is where I first saw Thee-O and Nicholas Bennison Spin and heard the anthemic Yomanda - Synths & Strings:
http://www.youtube.com/watch?v=BF2074PrqmI
Fox Theatre
Since I lived in the town over, Pomona was often a spot I went to at the last minute when the urge to party came over me. It is literally an old movie theatre with seats and space for a large movie screen. There's an upper deck where you could scope out the whole light shows and a dance floor that would slope downwards. At 5am when I would head to the parking lot, I'd turn around for a last look at the Fox and see Lucha Libre being advertised in the headlines for the next show. This is where I first listened to R.A.W. and went to my first free hardcore show.
La Casa
(Hmm, couldn't dig up a pick, but it was this huge old building, right
across the street from [another?] abandoned church. Spooky!)
Downtown LA, this place had wooden floors and a huge empty dance floor. I was told it was an abondoned church, as the place was a gigantic rectangle. The place was flooded with black lights and had the most air being circulated. Oxygen is always good. Still had black booger s though. It was the first place I listened to Christopher Lawrence who played more the more 'darker' drive trance.