Ride into town, caught the nine o'clock bus from the "Road Port" (a brand new deluxe bus stop near the city center). It took us (Claudia came with me) a little over two hours (we were expecting about an hour) to get to Chinhoyi Caves National Park.
Wonder Hole is the first "cave". It's actually a sink hole that has filled with water and is open to the sky, but you do walk down through a tunnel like cave to get to the view point. The water is stunningly clear and there are stalactites hanging from the roof of a grotto hanging over the far side of the water. Diving is allowed here, and we watched a group of divers swim down. The Wonder Hole is the start of an underwater tune that leads to another of the sinkholes.
Dark Cave is more of a proper cave. There's not much in the way of cave growth, but there is an underground sink hole that is the other end of the underwater tunnel. The "lake" has an amazing inner light. It glows a otherworldly blue from the light that comes in through the tunnel. It was pretty bizarre to watch the divers come from nowhere. the water is fantastically clear - it's difficult to tell where the air stops and the water starts. I'd love to do the dive, but there doesn't seem to be an organized dives.