Mountain Argopuro, Volcanic mountain in Probolinggo, Indonesia.

Gunung Argopuro is a volcano in Probolinggo district on Java, with its highest point reaching 3,088 meters (roughly 10,130 feet). Deep erosion valleys cut through the massif, dropping more than 1,000 meters (about 3,280 feet) into the older rock.

The volcanic massif has shown no confirmed activity for more than five centuries, with the last suspected eruption dated to 1597. Over time the caldera eroded and several secondary craters formed, now overgrown with vegetation.

Local tradition holds that Dewi Rengganis, sister of Nyi Roro Kidul, dwells at Puncak Rengganis, the mountain's best-known summit in Kalianan village, Krucil district, Probolinggo regency. The highest point, about 200 m south of it, is called Argopuro and carries a triangulation monument.

The ascent is described as the longest trek on Java, covering about 63 km, so plan several days on the trail. The highest point, Argopuro, lies roughly 200 m south of the better-known Puncak Rengganis and is marked by a triangulation pillar. The massif sits in the Iyang-Argapura wildlife reserve, between Gunung Raung and Gunung Lemongan.

Multiple craters lie scattered across the entire massif, forming different elevation belts where distinct plant communities have developed. Mosses and ferns grow between the cones, while higher zones show open grassland.