the entrance or exit of a cave formed in limestone in a maltese valley - ghar il-buz, malta

small cave entrance limestone karst landscape caving natural and plants eroded erosion weathering malta maltese islands countryside dry valley cove dug in the ground room rock rural trekking birzebbuga wied mixta cavern underground hidden geological formation red soil seeking shelter safe dark outside world cloudy day sky smooth wall out of coming tunnel exit reddish earth light end