Due to our 10th Anniversary of Geocaching in October 2012 we are making a Series of Slovenian VOR/DME caches. Fourth and the last in this Series is POR (In communications it is PAPA OSCAR ROMEO) VOR/DME station located near Portoroz.
If you are interested just in quick found cache stop reading now! And go for cache hunting. 
Picture of VOR/DME station
If you are interested what the VOR/DME stations are, read further!
From cache location looking West you will see a POR VOR and DME building. Since the station is near International Border and Airport you can't go to the building. The "code name" VOR/DME POR short for VHF Omnidirectional Radio range with Distance Measuring Equipment. It is a radio beacon. It comes from the 1950 era where there was no GPS sistem. From 2000 when president Clinton turned off SA GPS system became more used in airtraffice navigation too. Like in Geocaching :)
Airplane pilots are usually not relying on GPS signals for determinating their position but on measurements based on radio signals sent from ground stations. These stations are commonly referred to as navigational aids, short "navaids". There are basically two different types of ground stations used for this purpose. VORs are used for determining directiions from or to VOR statiions, DMEs are used for determining distance from DME stations. With VOR and DME a single ground station is enough for position determination.
On the left is schematics of an Airplane flying from VOR station. On the right there is VOR instrument in the Airplane.
Airplanes are using their own navigation charts where VOR/DME stations are used as IMPORTANT Crossings.
In the middle left is VOR/DME named POR - Portoroz.
For better understanding of importance VOR/DME stations there is detail of POR VOR/DME. Each VOR/DME station is described with name (Portoroz), frequency (115.15), sign (POR), morse coded sign (._ _. _ _ _ ._.) and often GPS position - N45 28 29.19 E013 36 43.51 (on VFR charts GPS position is not included)
In Slovenia there are 4 VOR/DME stations. And POR is the fourth and the last one in this series!
Caution! Please be careful not to fall in Canal Grande (old Dragonja river)! Please keep hidding place the same as you found it.