El Peñón de Guatapé, Inselberg monolith in Guatapé, Colombia

El Peñón de Guatapé is a granite inselberg in the municipality of Guatapé, Antioquia Department, rising above the surrounding hills and reservoir. The pluton consists of a single smooth granite surface with vertical cracks running from the ground nearly to the summit, where a viewing platform stands.

Luis Eduardo Villegas López, Pedro Nel Ramírez and Ramón Díaz made the first official ascent on 16 July 1954, after a five-day climb using sticks wedged against the rock face. Villegas later bought the rock from farmers who considered the land useless for farming, cut stairs into a crack and charged visitors to climb. In the 1940s the Colombian government had already declared the rock a National Monument.

The western wall displays a large white letter G and an incomplete U, traces of an old dispute between two towns over the rock's name. Today, visitors climb the stairs and take pictures of the colorful houses of Guatapé far below, while locals sell souvenirs and refreshments at the base.

The staircase of more than 700 steps winds through the natural crack in the granite, and the climb takes roughly 30 to 45 minutes for most visitors. The viewing platform at the top is small and can get crowded with many tourists, so early mornings or late afternoons are often calmer.

The granite supports almost no vegetation on its surface because the rock is too smooth and steep to hold soil layers. The only exception is a few lichens and mosses in the cracks, which have spread slowly over decades.