Whether or not Zhoukoudian is that optional item off your Beijing Bucket List, it’s still worth visiting as further north (around 30 min driving) will bring you to a fascinating destination: the Shihuadong or the Stone Flower Cave. The seven-layer underground cave system spans an area of 1.8 hectares and has spectacular halls full of different types of stalagmites, stalactites, and limestone pillars. Don’t miss the fourth underground layer where you can see the eponymous "stone flowers," or newly formed stalagmites with needle-like appendages that resemble fresh snowflakes. Beyond that, the cave gets steeper. The cave is cool, at around 13-15 degrees Celsius all year long, so it’s a great destination during the summertime.