Laguna Brava (Spanish for wild or rough lake, Spanish pronunciation: [laˈɣuna ˈβɾaβa]), also known as Yolnabaj is a karstic lake in Guatemala.

It is situated in the municipality of Nentón (Huehuetenango), close to the border with Mexico.

The lake is fed by several streams and subterraneous watercourses.

[1] The area around Laguna Brava has been inhabited by Mayan communities of the Chuj ethnicity since the 19th century.

[2] In the year 2000 a conflict over land usage emerged between indigenous communities depending on the land, and the American owners that just acquired it in order to transform it into a nature reserve.