Kosynthos is connected with the 8th Labour of Hercules : Mares of Dioemedes. I copy from http://en.wikipedia.org/wiki/Labours_of_Hercules where you can take an idea for all Labours.
Mares of Diomedes
After capturing the Cretan bull, Hercules was to steal the Mares. In one version of the story, Hercules brought a number of youths to help him. They took the mares and were chased by Diomedes and his men.
Hercules was not aware that the horses, called Podagros (the fast), Lampon (the shining), Xanthos (the blond) and Deinos (the terrible), were kept tethered to a bronze manger because they were wild; their madness being attributed to an unnatural diet of human flesh.[8] Some versions say that they expelled fire when they breathed. The horsed get their strength by drinking water from RIver Kosynthos (Ancient name : Kossinitis). They were man-eating and uncontrollable, and Hercules left his favoured companion, Abderus, in charge of them while he fought Diomedes, and found out that the boy was eaten. In revenge, Hercules fed Diomedes to his own horses, then founded Abdera next to the boy's tomb.
In another version, Hercules stayed awake so that he didn't have his throat cut by Diomedes in the night, and cut the chains binding the horses. Having scared the horses onto the high ground of a peninsula, Heracles quickly dug a trench through the peninsula, filling it with water, thus making it an island. When Diomedes arrived, Hercules killed him with an axe (the one used to dig the trench), and fed the body to the horses to calm them.
Both versions have eating make the horses calmer, and Hercules took the opportunity to bind their mouths shut, and easily took them back to King Eurystheus, who dedicated the horses to Hera. In some versions, they were allowed to roam freely around Argos, having become permanently calm, but in others, Eurystheus ordered the horses taken to Olympus to be sacrificed to Zeus, but Zeus refused them, and sent wolves, lions, and bears to kill them. Roger Lancelyn Green states in his Tales of the Greek Heroes that their descendants were used in the Trojan War. After the incident, Eurystheus sent Heracles to bring back Hippolyta's Girdle.
The Cache
Leaving your car into the Parking Lot you can pass a small wooden bridge and follow to the left a short path for around 500 meters. You will reach a hut about 50-60 meters above of the street level and around 260m above the sea level. From there you have a very nice view of Kosynthos River. You can feel like the Master of th Kosynthos from this point. Its like you can order and the river obeys. (Actualy in our days it is not a river but a stream that some times in summer it does not have water) but this is not a problem to feel like The Master of the Kosynthos LOL
In front of the hut you can see a "double strairs type" rock. I mean that there is a double rock which looks like a twin strair with only 2 steps. Somewhere there is the cash. The cash itself is a small white container that contains only the logboog and some instructions for the muggles and also a small marble ball as a giftto the FTF geocacher. As it is a small container there was no room left so please bring your own pen.
If you intent to visit the cach in summer time please be aware of the fact that the cache is in a forest with rocks and leafs so there is always a posibility to meet a snake. Also please be aware of the sliding rocks.
You can also use the trail in my trimble outdoor site : http://www.trimbleoutdoors.com/ViewTrip.aspx?tripID=2059503&secretLinkKey=5abbd18c-9318-41a7-9a29-5dfde847f25f
Greek geocachers can also check my blog : http://baxygr.blogspot.gr/2012/12/the-master-of-kosynthos.html for further details in Greek.
New path open recently. It has easier access. No excuse now :) . Check trimble outdoors : http://www.trimbleoutdoors.com/ViewTrip.aspx?tripID=2853395&secretLinkKey=d78dda25-3e88-4ef1-9f9d-bc8cf53ce378