Lake Sassolo, Alps By Franco Banfi

The ice forms into comb like structures and tiny tunnels are made between the metre thick slabs, allowing the divers to squeeze through and capture these unseen views.
'The water in the lake is freezing, so the best time to go is summer,' said Franco Banfi.
'But it's so different from a lot of other dives you could do around the world that it's well worth a visit.