Cacti enjoy a lot of light, so it is best to place them in a spot where they get it. Next to a south-facing window is the ultimate spot for your cactus, although make sure to move them if they are getting too much direct sunlight and showing signs of sunburn. Normally cacti don’t thrive in the bathroom, as it is too humid, but, aside from that, you can pretty much place your cactus anywhere you think it looks best!