The World War II Caves. Most tourists visit the Seige Tunnels and St Michaels Cave duing their stay in Gib, but enquire at the Rock Hotel with regard to seeing more of the tunnels. There are a select few who offer tours within other parts of the tunnels built during the first and second World wars. These tunnels include generators in amazing condition, hospital wings, nissan huts and lots more. Tours are few and far between and may last for more than three hours.