Best to wear a comfortable shoe and something that will help you from slipping as certain area of the tour are wet. We wore tennis shoes and had no troubles. I saw no one while we waited or as people that came back from the tour wearing sandles... but doesn't mean you can be a trend setter.
If there has been rain recently, the cave floors will be muddy, so it's a good idea to wear sturdy shoes that you don't mind brushing a little mud off when you finish the tour.
Wear anything that you are comfortable with walking for long time.
Open toed shoes are a bad idea and not allowed on certain types of tours
They say comfortable shoes are best. We all wore our old comfy sneakers. It is wet inside and it can be slippery.
Thanks! Your answer is awaiting moderation.