Named after the Australian Prime Minister, Harold E. Holt, who died in office: a VLF (19.8 kHz and 1 MW power) station that provides communications to the Australian and US Navies plus allied vessels in the western Pacific and eastern Indian oceans.
Although it doesn't appear so, the tallest masts (at 364 m - almost 1200 ft) are higher than the Eiffel Tower and Empire State Building!