Lagoon

Lagoon (Lat. laena, 'a hollow,' 'a pool') is a species of lake formed by the overflowing either of the sea or of rivers, or by the infiltration of water from these; and hence lagoons are sometimes divided into fluvial and marine. They are found only in low-lying lands, such as the coasts of Holland, Italy, the Baltic, and the east coast of South America; are generally shallow, and do not always present the same aspect. In some cases they are completely dried up in summer; in others, after being once formed, they preserve throughout the whole year the character of stagnant marshy pools; and in others again the sea, which re-unites them to itself in winter, is separated from them in summer by a bar of sand or shingle.