One place to go is Spinalonga Island (re-named Kalidon/Kalydon in 1954). It is an ancient fortress first built to protect ancient Olous, once one of the most important towns on Crete, especially between 3000-900 BC. 

In 1030 Spinalonga was one of the most powerful, least penetrable fortresses on Crete. Spinalonga is not its original name. The Venetians adapted Stin Elounda (go to Elounda) in to Spina (thorn) Longa (long) because they couldn't understand Greek. In 1574, a new fortress was constructed, the original wooden model can be found in the Venetian museum.  

The island was  a refuge to Christians under threat from Saracens. During the latter days of Turkish domination, it also became a secure place for Turks in fear of reprisals from Christians. The Turks tried to attack the Greek rebels (unsuccessfully ) on the 'mainland.'  Turks from Mirabello, Sitia and Iearapetra went to the island.  Most of the  Turkish residents left  the island by 1903, when Crete united with Greece. That year lepers were relocated to Spinalonga from Miskinias near Heraklion and from all over Greece. The last of the lepers left the island in 1957 when at last a cure was found for the disease. Those with families were able to return to their homes. 

Lepers brought people from Elounda and Plaka as laundry staff.  The Plaka/ Elounda residents were poverty -stricken and had no choice, they were exploited. Some lepers had as great a chance of survival as the starving residents on the 'mainland' due to shortages of both food and water. Some lepers ran profitable businesses and were provided with food, clothing and funding. The truly sad fact is the children born to lepers were taken away and adopted out or sent to family members. The government ensured the children  were provided with jobs later on.

The restoration work being is being carried out by the Archaeological Department of the Government. Some of the Venetian bulidings were restored by the Turks. Spinalonga became a leper colony  to rid the island of Turks who didn't want to leave after Crete gained independence in 1913.  There are still survivors of Spinalonga living in the Elounda area.(Oct 2006)

below is a link to more photographs of Spinalonga; you need to key in Spinalonga in the search box  as the link does not go directly to   photograhs of JUST Spinalonga.

http://www.flickr.com/photos//tags/sp...

    

Getting there: Go to Plaka and get the boat across. Only takes 5-10 minutes and costs about €8 per person. €2 to go in. Beautiful and fascinating with stunning views of Plaka and Elounda.

You can also get a boat from Elounda to Spinalonga.it takes about 20 minutes and the cost is 10euros

There are also boat trips arranged from Agios Nikolaos, some include a barbq on a secluded beach so prices vary.

If you have read The Island by Victoria Hislop it is interesting to see the places mentioned; whilst the characters/story are fiction the places and events are real. Very humbling to realise that lepers had to live and die here.

An excellent book to read for a more accurate account of the life of the lepers on Spinalonga is Yannis by Beryl Darby. Fiction but accurate as a result of the author meeting with a former "leper" who had lived on Spinalonga.