Valle Vinales once covered by a mountain limestone range, much has eroded and left the mogotes. Lots of the mogotes have caves and some of these are developed for visitors.
Best during the dry season roughly from November to April but this is also the peak season. Shoulder season May and June is worth a try and less crowded. Showers may occur but easier to find a nice casa without booking in advance. Hiking at the rainy season is possible but expect flooded trails. You might cross rivers with high level. Avoid the cyclon season from July to October and the school holiday from July to August.