Dane Coombe is now called Deancombe. The Dane/Dean Combe Brook is now called the Narrator Brook.
A Cache is a stone built structure, often roofless, used by tin miners to store equipment. These were found on Dartmoor in areas where tin mining was common.
Crossing tells us in his //Guide to Dartmoor// that the caves were probably made by the tin miners and may have been the location of an illegal still for distilling alcohol. He also says that local farmers later used the caves to store potatoes.