The only place I saw these plants was at Baku National Park in Borneo. Initially I thought the pitchers were the flowers, but when I was told they are abnormal leafs, I liked this exotic plant even more. In the park there are many kinds of pitcher plants which each looked differently beautiful.
If you ever decide to travel Borneo, make sure you see Baku National Park and make sure you do one of the longer day tracks. It was really exhausting but it was also one of the most beautiful, nature-touching and adventurous tracks I did.