The channel is a natural phenomenon and was named after Saint Anthony the Abbot. It is the only natural water route to Šibenik.
From the sea or the opposite shore you can see two holes in the coast, which locals call “Hitler’s eyes.” These are the entry into an underground water bypass built by the Germans in the 20th century. This construction allowed military boats and torpedo boats to access or to leave the city of Šibenik by water and to bypass underwater-located mine barriers during war times.
Information that it was used by submarines could not be true as the radius allows only smaller vehicles to pass. Today an iron curtain prevents boats from entering.
Luckily, the site is accessible by foot on a path crossing a small bay and a natural cave. If you walk through the tunnel have a look at the handrail, which is actually a former train rail.
Know Before You Go
Access from land is possible on a small trail starting at 43.726787, 15.873372. Cross the small bay and walk through the cave to one of the two entries to the tunnel.
Above the bay, there is also a small chapel dug into the rocks.