He returned to mountaineering, and since 1999, has led more than 15 expeditions, including the first all-Singapore ascent of Argentina's Aconcagua (6962m), and the world's third solo of Ojos del Salado, the highest volcano in the world (6893m).
He continued to participate in mountaineering expeditions, including one to survey Ojos del Salado (6,893 m) in 1956, several trips to the Cordillera Blanca in Peru, and a second expedition to Nanda Devi in 1976, which he co-led with Louis Reichardt and Willi Unsoeld.
He ascended the highest peak Donja Ines (5,075 m) in the Cordillera de Domeyko and Ojos del Salado (6,893 m), the highest volcano on the earth.
Copa del Rey | Viña del Mar | Mar del Plata | Bassano del Grappa | Santiago del Estero | La forza del destino | Valle del Cauca | Guillermo del Toro | Tierra del Fuego | Museo del Prado | La fanciulla del West | Pinar del Río | Valle del Cauca Department | Pinar del Río Province | Lanao del Sur | Accademia delle Arti del Disegno | Viña del Mar International Song Festival | Università Cattolica del Sacro Cuore | Riva del Garda | Davao del Norte | Consistori del Gay Saber | Davao del Sur | San Juan del Sur | Benicio del Toro | Rojos del Águila de Veracruz | Mario del Monaco | Del Rio, Texas | Buenaventura, Valle del Cauca | Zamboanga del Sur | Punta del Este |
This is most likely the second highest crater lake in the world, and also the third highest lake of any kind in South America, behind the crater lake of Ojos del Salado and the small lagoon in the col between Tres Cruces Sur and Tres Cruces Norte.