As the name says, Isco is located in the neighborhood of Bica, very close to Bica funicular. Isco means "bait." Isco is a perfect restaurant to go to with friends, since there are plenty of petiscos to share.
In this eatery, the menu consists mainly of fresh fish and seafood; and what is on the menu each day depends on what has been caught. Everything is always tasty. If available, I recommend the mussels with bread, because I love to dip the bread in the sauce. Try a few dishes but make sure to leave space for dessert (their names are quite peculiar).
When you enter, you might think you are at a fisherman’s house, since the colorful space is full of fishing buoys, rescue buoys, and fishing pots. Don’t worry if they are full, just take a ticket and perhaps ask for a cocktail while you wait...you really don't want to skip this place.