Hi,
They are pointed to via /etc/named.conf in exactly the same way as forward zone files. For example :
zone "1.0.10.in-addr.arpa" IN {
type master;
file "domain.com.rr.zone";
allow-update { none; };
};
(That would be a reverse dns for the 10.0.1.0 subnet . )
So, both forward and reverse zone files would be physically in /var/named (or whatever other 'directory' is listed under options in /etc/named.conf).
Hope this helps