Best beach combing spots in Dubrovnik

Hello everyone. I was wondering if anyone had any information on where the best beach combing spots are for the dubrovnik beaches. Beach combing (collecting items from beaches like shells, rocks, marbles, sometime ceramic pieces or frosted glass depending on the location) is one of my favorite hobbies, and since I've not really a huge traveller, it is one of my priorities to find some spots ideal for this activity in Dubrovnik! If anyone has any information of any specific spots they recommend, please let me know as I leave soon. Thank you!