precise international border, is also the highest point in Venezuela outside of the Andes. Elevation measurements For 39 years, based on an uncontested measurement performed in 1965 by topographer José Ambrósio de Miranda Pombo, using a theodolite, the elevation of Pico da Neblina was thought to be , but a much more accurate measurement performed in 2004 with state-of-the-art GPS equipment by cartographer Marco Aurélio de Almeida Lima, a member of a Brazilian Army expedition, put it at . This was then officially recognised by the Brazilian Institute of Geography and Statistics (IBGE), the federal government's official geographic survey and census agency, which jointly organised the expedition. In February 2016, IBGE slightly revised again the official altitude of Pico da Neblina to , a 1.52-metre difference. There was no new expedition or field measurement at the time; the new value is simply a mathematical recalculation of the altitude, based on the previously obtained GPS field data, taking into account a newly available, more precise mapping of the Brazilian territory regarding the geoid (the imaginary surface based on the Earth's gravitational field that is the reference for altitudes). This explains why Pico da Neblina and Pico 31 de Março, which are next to each other, had both exactly the same altitude correction. Geology and topography The Neblina Massif is composed of a tilted block of sandstone overlying Precambrian metamorphic rocks. The peak is an impressive sharp rock pyramid or tooth, towering high (when the peak is visible) over the nearby lowlands on the Brazilian side, as the Imeri range quickly rises from only about 100 metres above sea level to about 2,000 metres at the base of the peak in just a few kilometres; from there the peak rises sharply. The Venezuelan side of the massif is hillier and the altitude gradient to the northern plains is less abrupt, although deep chasms and high walls still exist. Neighbouring Pico 31 de Março can be considered a secondary summit of Pico da Neblina; it has a smoother, rounder shape and is sometimes difficult to be clearly distinguished from Pico da Neblina on photographs, depending on angle and distance. Due to Pico da Neblina's equatorial latitude, while it can be cold on top, sub-freezing temperatures and frost appear to be rare (no permanent measurements are undertaken), and there is no snow. One non-authoritative source gives an average temperature of during the day and