Edinburgh is the city especially famous for a large street party during its Hogmanay New Year's Eve celebration.
Edinburgh's Hogmanay is a major Scottish festival featuring concerts, a torchlight procession, a large street gathering, and fireworks near Edinburgh Castle. The city center's historic setting gives the event a distinctive backdrop, while the celebration draws visitors from Scotland and abroad.
The festival developed from Scotland's long-standing New Year customs and was organized in its modern large-scale form from the 1990s. Its program has changed over time, but the combination of music, outdoor crowds, and midnight fireworks remains central.
Glasgow, Aberdeen, and Dundee also hold New Year's events, so the answer is not “Scotland” generally or every Scottish city. Edinburgh is the specific city most strongly identified with the internationally publicized Hogmanay street party.