This end-loaded piston-cylinder apparatus is designed for high-pressure experiments, simulating conditions found deep within the Earth's interior, including the crust and upper mantle. The system can accommodate lower pressure, large-volume experiments, and also a smaller volume cell to reach maximum pressures of 3 GPa (30 kbar). An experimental charge, typically sealed in an inert metal capsule (e.g., Pt, Au, or Ag), is enclosed within a pressure medium like NaCl, which deforms to ensure uniform pressurization. A graphite cylinder acts as the internal furnace, heating the sample, while a hydraulically operated piston applies pressure. Temperature is continuously monitored using a thermocouple positioned just above the capsule. Experiments are rapidly quenched by cutting the power to the graphite heater, making this apparatus suitable for studying igneous and metamorphic petrology, material synthesis, fluid equilibria, and element partitioning under extreme conditions.