The Lagoa das Sete Cidades is located in the island of São Miguel, on the Açores archipelago, close to the locality with the same name, and it is the largest freshwater lagoon on the archipelago, with a length of 4.2 km2 and a depth, which reaches the 33 meters, being one of the most appreciated natural heritages in Portugal.

It is consisted by two lagoons, the Lagoa Verde and the Lagoa Azul, connected together and surrounded by a landscape of great natural beauty, with more than 10 kilometers in diameter over a volcanic crater and surrounded by abundant vegetation.

The margins of the lagoon have very sloping slopes, being possible to find in the same, traces of the primitive vegetation of the Açores. In the Flora, it highlights the presence of the holly, of the mountain grape, of the cedar from the woods, of the Angelica, of the queiró, of the hydrangea, of the heather, of the flaky and of the daisies.

In the waters of the lagoon, there are several species of introduced fish such as the pike, the carp, the trout, the perch and the redhead fish. The Lagoon is also an important area of passage for migratory birds, many of which are in danger, being that there are also endemic birds of the Açores, as the blackbird, the estrelinha, and the Wood-Pigeon-of-the Açores.

In 2007, the Seven Cities Lagoon, as well, its surrounding area was declared as one of the 7 Wonders of Portugal, in the category of Non-marine wetlands.

The Lagoon is also classified as Protected Landscape of the Natura Net 2000, being surrounded of an extensive green area and of beautiful steep slopes, covered with flowers and trees.

In the plan part of margin of the Lagoa Azul, is located in the parish of the Sete Cidades, which still today maintains its the charm of the 19th century and where it highlights the traditional houses, some still with the bulk of high feet, as well, the Church of São Nicolau, of the neo-Gothic style, opened in 1852, and the house of the heirs of Caetano de Andrade, a descendant of the richest landed aristocracy of the island of São Miguel, heir to great wealth, in which are enlarged big properties in the west part of the municipality of Ponta Delgada, in island of São Miguel, with highlight for the Sete Cidades.

Associated to the Lagoon, in particular, to the different color of its waters, there is the legend of the Princess of the Blue Eyes, in which, it says that, where actually it is located the parish of the Sete Cidades, there was a kingdom, in which lived a young Princess, named Antilia.

During one of his usual walks through the meadows of the region, the princess met a shepherd with green eyes, being that with the passing days, the two young met, becoming more and more passionate. However, after becoming aware of the existing connection between both, the King forbade his daughter to return meeting with the shepherd.

Desperate, Antilia has requested his last meeting with the young man, in which, as they talked and said goodbye, they were crying his sad destiny, so that from the blue eyes of the princess, has formed the Lagoa Azul (Blue Lagoon) and from the green eyes of Shepherd, it formed the Lagoa Verde (Green Lagoon), having the felt tears of the Princess and of the Shepherd, became forever connected to the Lagoon.