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🇲🇾 Malaysia · Slim River, Perak
♨ Temperature
104°C
⛰ Altitude
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⚗ pH
—
💧 TDS
—
🌊 Flow rate
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📅 Established
A natural geothermal spring heated by deep granite intrusions along the Main Range (Triassic Main Range Granite belt); noted in geological literature as Malaysia's hottest surface-outflow hot spring.
✓ Verified on 2026-08-02
Ulu Slim Hot Spring, in Kampung Ulu Slim near Slim River, Perak, is recorded by the Geological Society of Malaysia as having the highest surface-outflow temperature of any hot spring in the country, reaching approximately 104°C at the vent. Its heat comes from deep granite intrusions along the Main Range rather than volcanic activity, which is why the water has little sulphurous smell despite its extreme temperature. The site is undeveloped — free to visit via a walking path leading to four pools, with an informational poster board but no bathing facilities, since the water is far too hot for direct soaking. Researchers have studied Ulu Slim for its geothermal energy generation potential.