I found this here:
I am in Brisbane, Australia. The furtherest point from me is at -26.972108°N, 27.46758°W, which happens to be in the Atlantic Ocean. The closest land is the island of Il Hierro, of the Canary Islands, off the west coast of Africa.
El Hierro's western end was for a long time considered the end of the known world by the Europeans. At this end I will be furtherest from where I am now.