The Templars built an escape tunnel from Akko fort to the ocean in 12th century. The site was discovered in 1994, and even today you’d be impressed by this tunnel!
Access-free facility available.
Don’t forget to come here with your combined ticket after visiting Akko fort.
This is the entrance to the tunnel~ It doesn’t look too impressive, but it’s quite fun down there! They sell entrance ticket for 15NIS here, but this attraction is already included in your combined ticket to Akko fort (40NIS).
It’s not easy to find. Google Maps GPS doesn’t work well in the old city. And the entrance isn’t on the map… 
I locate myself in Khan Al-Umdan first, then followed the signs.
There are some stairs (but it’s accessible as there’s an elevator). Animations showing the history of how crusaders got here.
There are two tunnels actually! Still remodeling as of 2018. This isn’t the path opened to tourist. Haha! Don’t worry!
Now, this is the way prepared for tourists. Crusaders conquered Jerusalem from the hands of Muslims in 1099. One of the “order” is called “Templars”. Their role was to take care of patients and pilgrims. But soon, very soon, in 1187 Salah Al-Din defeated crusaders again! So the Templars retreated to Akko!
This tunnel would have connected the fort to the Mediterranean Sea!
In 1291, Akko was destroyed and was renovated in the 18th century. And this tunnel was discovered in 1994 because someone had a sewage problem, And voila, this tunnel with 800 years of garbage and waste was found!
350 meter is not that long, but I was impressed the first time I came here!
Yay! This is the exit! The sea! It would have been nice if the weather wasn’t like this! 
This is what the exit looks like.
The port at night! The lighthouse is right in the background, and you feel the beauty of this ancient city!
