No, this isn't some hi-tech torture dungeon: it's the Maxwell Test Chamber at the European Space Agency in the Netherlands. It's used to simulate the vacuum of space for satellites. Inside, no-one can hear you scream.
The spikes are made of foam, and serve to absorb any internal signals from satellites that are being tested. That, combined with the metal Faraday cage wired into the walls, means it's a electromagnetic dead zone, perfect for testing sensitive equipment. According to the ESA:
Once its main door is sealed, the metal walls of the chamber form a 'Faraday Cage', screening out external electromagnetic signals. The 'anechoic' foam pyramids covering its interior absorb internal signals – as well as sound – to prevent any reflection, mimicking the infinite void of space.
The satellite's systems are then switched on to detect any harmful interference as its various elements operate together.