The 193m (625ft) high Loran-C mast near Olonkin City, Jan Mayen.
It transmits it's long range pulses at 70000 watts (some transmitters peak at 4000000 W!), so do not climb!
Photo taken from within it's range of anchor wires, so some of them reaches the ground behind me,
and hence some of them goes upwards in the picture frame.