Here’s something you don’t see everyday: A giant, steaming lake of lava.

The lava lake looks like a giant tar-filled sink hole in Halemaumau crater, on the summit of Kilauea, one of the world’s most active volcanoes. Scientists on the Big Island are tracking it and say lake levels have been rising steadily in recent weeks. The lake has risen about 50 feet, now sitting about 250 feet below the crater floor. The lava is in near constant motion and sounds a lot like crashing surf lava gases are released. (Scientists recorded the sounds from the lava lake on Feb. 14.) The explosions can send lava several hundred feet into the air.

Read it at Our Amazing Planet.

Here’s a slideshow with recent pictures of the crater: