Mostly for Chuma's benefit:

The ErrorLog directive (in httpd.conf) specifies the pathname of the error log.

I haven't changed the default. Here's mine (including the preceding, important comments re <VirtualHost>):

#
# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost
+>
# container, that host's errors will be logged there and not here.
#
ErrorLog "/private/var/log/apache2/error_log"
[download]

The CustomLog directive specifies the pathname of the access log. It has much the same comments re <VirtualHost>. Mine's called access_log and is in the same directory as error_log.

For poj:

You were effectively correct with the location: /var is a symlink to /private/var.