The Pentadio Hot Springs geosite has main geological features of hot springs and secondary geological features of Hundulobohu Hill. Pentadio's type of geothermal manifestation is a hot spring. All hot springs have a pH of 6, are colorless and tasteless. Some hot springs are odorless, some smell of sulphur. Pentadio geothermal fluid emerges to the surface in the form of hot springs through geological structures that form fractures in the Gorontalo graben zone.
Figure 1. Pentadio hotsprings.
Figure 2. Limboto Lake (Photo: Andrini).
Pentadio Geothermal is one of the geosites located on the plains of Lake Limboto. In the northern part of the Pentadio geothermal manifestation there is an isolated hill form. The isolated hill known as Hundulobohu Hill is composed of tuff lithology, limestone and non-compact materials such as clay. In the southern part of Pentadio Hotspring, there is Limboto Lake with its unique biological, cultural and intangible heritage.
Figure 3. The river estuary is where Pentadio's hot water meets the cold water of Lake Limboto (Photo: Andrini).
Hot water sourced from Pentadio hotsprings flows to form a hot spring river and empties into Lake Limboto. The meeting of hot water from Pentadio hotspring with cold water of Lake Limboto is a location rich in fish because the temperature is warm.