Stockholm, Sweden
Stockholm Inner-City
18 Square miles (46 square km).
13 is land the rest is water.
Population: 346,538
About 40% of the city population and 15% of the greater/metro-population.
Consists of Gamla Stan (Old Town), Kungsholmen, Långholmen, Norrmalm,Riddarholmen, Skeppsholmen, Södermalm, Vasastaden, Östermalm and Djurgårdsstaden.
Its basically the continous city-blocks that are visible on google maps. You can see a distinction between the innercity (inre staden) and the outer boroughs (ytterstaden) by the density and the way its built. It started with the old town in the middle and then stretches up to the northernmost part of Norrmalm, and the southern most part of Södermalm. At both of these edges are what we call the "Tolls" which works as the borders in to the actual inner-city.
Example of architecture:
