You should be able to find these delicious summer rolls in any part of Vietnam. However, their Vietnamese name may be different depending where you are. In the north, they often call them nem cuốn (nem rolls). In central Vietnam, they may be referred to as bánh tráng cuốn (rice paper rolls). In southern Vietnam, they will probably be called gỏi cuốn (salad rolls). On top of all that, there are different variations that make everything that much more confusing. The standard roll comes stuffed with greens - usually mint, cucumber, lettuce, chives, basil, perilla - plus some pickled daikon and carrot, sometimes some vermicelli noodles, and of course a protein which can be slices of pork loaf, shrimp, tofu, grilled pork, etc. They will be served with a dipping sauce (nước chấm) that's a combination of sweet, sour, spice, and salt that will leave you double dipping (which apparently is okay in Vietnam).