Impressive
The Great Siege Tunnels, Things to see in Gibraltar, Gibraltar
It's hard picture the conditions under which these tunnels were excavatated in the late 18th century. Although you can't see all 30 miles of tunnels it is well enough to explore the public one which is a few hundred meters deep - the walk uphill back to the entrance was actually a bit exhausting. You'll explore the tunnels by yourself which is a bit of a shame, it would have been very interesting to hear some stories from WWII. There are of course some information posters but to be honest they were sometimes hard to read since the ink had dried up and disappeared. But anyway, the tunnels are worth a visit if you visit the Rock itself.
