Asphalt is the same material used to pave roads and runways. At Pitch Lake, it has been oozing naturally out of the earth for thousands of years. The surface looks dark and solid, but if you stand still for too long in the same spot, you slowly start to sink - so visitors keep moving!
Scientists have found tiny living things called microbes deep inside the asphalt. These microbes survive without sunlight or oxygen, which is very unusual. Studying them helps researchers understand how life might survive in unusual places elsewhere in our solar system.
People have been collecting asphalt from this lake for a very long time, and yet it keeps refilling itself. Experts think there is a huge underground reservoir pushing the asphalt up from below, a bit like squeezing toothpaste from a tube that never runs out.
Pitch Lake is one of Trinidad's most famous landmarks. Tour guides walk visitors across the surface and show them spots where warm, clear water bubbles up through the asphalt - making strange little pools right in the middle of the black lake.