unless you are severely constrained by the size of your storage media

Digital Dodging & Burning

Should you delete the extra shots right away? No, if storage permits, keep all three shots until you get home and upload them to your PC and into an image editing software, such as Photoshop. By using the layers functionality of Photoshop (or similar functionality of another image editing software), you can load all three shots into different layers and then carefully erase the under-exposed or over-exposed part of one or more layers to end up with a final shot where both the main subject and the surroundings are properly exposed!

This Photoshop functionality allows you to shoot in very extreme lighting situations where there are many parts in different intensity of light and shadows such that you are losing details in the highlights and shadows. In this case, you might need more than two extra shots to obtain details in the different parts. Without moving the camera (a tripod is essential here), take as many shots as you need, exposing for the different parts you want details to be visible. Then you would load them all up into Photoshop, each into its own layer, and by erasing the under- and over-exposed parts in each layer (granted, this equivalent of film 'dodging' and 'burning' can be a very tedious and challenging task in itself, but done properly it can be well worth the effort), you can end up with an 'impossible' shot where every part of the cave is properly exposed.