The name of the mall with a food court, and cinemas is pretty impressive. I wrote a little in the blog about visiting in November. I remember this mall from a long time ago. In fact, it's 33 years old this year.
Now there are competing new shopping malls but this one is in a good location and makes for an interesting stop, perhaps for food or a movie.
The area is on the Galle Road in Colombo 4. That number may not help you much in figuring out the exact location. Colombo has always had designated administrative numbers, and they've never made a lot of sense to me. For example, Colombo 6 and Colombo 13 share a common border. Still, of course, locals know where each is.