New to Java

I am working with a server on which someone else installed Apache. In fact, they have both Apache 1.3 and Apache 2.0 on it. Only Apache 2.0 is active. I don't know what they used to install it or where Apache came from. The people who installed it cannot be reached.

How do I find out which directory is Apache_home?
At first I tried looking for files and directory names that I thought would show up in the Apache_home directory tree:
Tried 'locate apache' in root, and got dozens of directories or files with the word "apache" in them.
Tried 'locate httpd.conf', and got two listings (etc/httpd/conf/httpd.conf and usr/lib/opcenter/fastcgi/httpd.conf). One might be for each of the Apache versions?.. but which is which?? Are either of them under the "apache_home" directory??
Tried 'locate libexec' (one of the directories Im need to find) and got user/libexec and user/local/libexec.

Is there a configuration file or something that has a statement like "$Apache2.0_home=XXX/XXX/XX" that would tell me where it is??

Thanks in advance.