There is a supermassive black hole at the center of our galaxy. There is also a lot of other stuff there as well. Young stars, gas, dust, and stellar-mass black holes. It's a happening place. It is also surrounded by a veil of interstellar gas and dust, which means we can't observe the region in visible light. We can observe stars in the region through infrared and radio, and some of the gas there emits radio light, but the stellar-mass black holes remain mostly a mystery.