Tumuk Humak Mountains

The Tumuk Humak Mountains (also written Tumuc-Humac or Tumucumaque) are a remote tropical mountain chain on the northern edge of Brazil that form part of the Guiana Shield. The range defines stretches of the international borders between Brazil, Suriname and French Guiana and consists of steep, forested uplands.

Access is limited and mainly by river or small aircraft; the area is prized for intact rainforest, biodiversity and river valleys rather than developed trails or tourist facilities. Elevations are modest compared with major tropical ranges, with many isolated peaks and plateaus covered in primary forest and numerous rivers that head in the uplands.

These mountains are composed of very old Precambrian rocks of the Guiana Shield and have not experienced recent major orogeny, remaining largely covered by continuous forest for millennia. Human presence historically has been sparse, with indigenous communities and only limited exploration and scientific surveys until modern times.

The range sits along the northern border region of Brazil adjacent to French Guiana and Suriname, in the remote interior of northern South America and far from major coastal cities.

• Remoteness and geology: Part of the ancient Guiana Shield, the range is rugged, heavily forested and sparsely populated with limited access routes.