I highly recommend a balance beam, if anyone has access to one. We have one at the playground, only 2-3 feet off the ground, with lots of sand underneath for falls. My 17 mo DD loves it! Mostly because when she gets to the end she knows she is going to fall off and that is so funny. (I cheat and hold her left hand for balance, also so when she falls I can "help" her fall the right way.) When they are this young they can walk on it really well. I think it is because they are so short that their center of gravity is just really easy to keep. And they've got that great curl-grab thing going with their toes. The only issue is also short attention span, so if an exciting dog comes by they forget where they are walking and fall off. But that is also the fun part!
What I am not really comfortable with is slides. Anyone else having trouble letting their DC take chances? DD loves slides, and now she can climb up, and slide down by herself and I need to let her be but it freaks me out a bit. At first I would helicopter and stand behind her because it was so hard for her to climb up the big ladders, and bigger kids would accidentally kick her in the head and she'd go flying to the ground. Then I would hold her hand on the way down, just in case she would lean back, but she only did that once. Now I sit on a bench and just watch, and I know it makes her happy and proud because she so enjoys doing it all herself. But it is still nerve racking.