 In 1965 and 1967, he was also a member of teams which undertook nautical archaeological research of Roman shipwrecks in the Mediterranean Sea off southern Italy and of an Iron Age "Villanovan" village in a northern Italian lake (Lago di Bolsena) in 1965.His interest in the Iceman led to his study in recent years of the role of sacred landscape in Neolithic religion in the central Alps.Johan first began mountain climbing in 1964 in the Alps and in the mid-1970s in the Himalayas, including participating on the successful 1976 American Everest Expedition and making a first ascent in 1979 of the South Face of Buni Zom (21,500 ft) in the Hindu Kush (Pakistan).