Forte do Macapá, Military fortress in Macapá, Brazil.

Forte do Macapá was a timber-and-earth fort (forte de faxina e terra) built on a point of land on the left bank of the Amazon, where a small redoubt had stood since 1738. Its plan was drawn by captain-engineer Gaspar João Geraldo de Gronfeld and the works were completed on 31 July 1761. From 1764 it was replaced by the Fortaleza de São José do Macapá.

A small detachment already occupied the Reduto do Macapá from 1738 under Manuel Pereira de Abreu. In 1761 Governor Manuel Bernardo de Melo e Castro ordered Captain-Engineer Gaspar João Geraldo de Gronfeld to design a timber-and-earth fort at São José do Macapá; works on the same point of land were completed on 31 July 1761. From 1764 this fort was replaced by the Fortaleza de São José de Macapá.

The site began as the Reduto do Macapá, a small detachment post held since 1738 under Manuel Pereira de Abreu. In December 1751 Francisco Xavier de Mendonça Furtado sent sergeant-major João Baptista do Livramento with Azorean settlers, supplies and tools to found the settlement and fort. The village became São José do Macapá on 4 February 1758.

The fort stood on a point of land on the left bank of the Amazon, in the old Province of Tucujus, where Macapá now lies. The 1761 fort of wattle-and-daub and earth was built on the same point where the 1738 redoubt had stood, and from 1764 it was replaced by the Fortaleza de São José de Macapá.

The five-pointed star shape was not chosen for looks but was specifically engineered so cannons could fire in every direction. This layout meant only a few defenders could cover all the ground surrounding the fortress.