There are ports that profit from a space which can naturally harbour the boats of the moment; Bruges or Ghent were relevant ports in a given time, but larger ships and the silting of their river mouths has changed that situation. And there are ports that are just a result of spectacular bays in which an entire fleet could be moored; when surrounded by a metropolitan area, the result can be simply spectacular in landscape and urban complexity terms. Large bridges with funny layouts (the bridge as the shortest span between two points can be distorted by the presence of a reef or an island on which to have a footing), the rush to occupy flat lands on the seashore (wharfs, airports, factories, infrastructure…) and a complex terrain elevation can be present.
Lisbon is one of the most interesting cities in the Iberian Peninsula and the whole of Europe when it comes to the relation between urban fabric and landscape. It is the sea gate to a watershed that covers a significant part of the central Iberian Peninsula. The Tagus estuary widens in the Straw Sea before going through the Almada- Alcantara straits, creating a gate to the sea that, by its sheer dimension, is at the same time a threshold and a visual opening. The empire is past, but its built remains are still interesting: Commerce square is an example of quality architecture by the Tagus shore, but it is by no means oppressive.
San Francisco has an even larger bay, formed by the confluence of the Sacramento and San Joaquín rivers. it is the natural outlet of the California central valley. The urban core is near the Golden Gate straits, but the visual link to the open sea is less relevant than in Lisbon. Conversely, the more reduced peninsula allows an urban façade (albeit rather low density and not formal at all) towards the open-sea beaches. There are skyscrapers, but no space seems to have the scenic relevance of Commerce square in Lisbon; the image, as in most American cities, is defined by stacking fragments, not by a unitary architectural project. Some recent projects, as the High Speed Train station, can have a powerful architecture, but not related to the sea. The most relevant recent project on the seashore has been a subtractive one: removing the Embarcadero freeway.
Rio de Janeiro configures an urban landscape of enormous complexity, whose qualities have been recently recognized by UNESCO through its inscription on the World Heritage List. The urban renewal project in Port Maravilha intends, among other ends, to transform a section of central wharfs, but here the most representative city-water interface is the beach. This does not mean Copacabana is the city core; it is a recognized image and a busy place, but not necessarily the kind of urban core you would assume in other countries. In socioeconomic terms, Rio still suffers after several decades of the impact of loosing its federal capital status to Brasilia.