Emerging as Istanbul's coolest neighborhood in recent years, Karaköy, once a port area that used to house fishmongers and hardware stores, will welcome fall with a three-day street festival starting on Friday.The Karaköy neighborhood has become a hot spot for the city's expats as well as its young people. Easy to access, the area is now an art haven housing international exhibitions and a cool neighborhood with cafes to gather with friends.The free festival will be held in Karaköy Marjo, where the street is adorned with colorful umbrellas. As in all other street festivals, the program will have live music, food and entertainment events along with other activities. The event will end on Sunday and guests are requested to fill a form before arriving at the festival venue.