Very nice flat with a stunning view. The journey over the dirt roads is a bit adventurous (the last 500m), but you can also park on the other side in Olympos once walk through the village. The flat is very well equipped and lacks nothing. The Wi-Fi is also reliable and fast. A small beach directly in Olympos can only be reached via dirt roads and a short walk. The beach in Diafani can be reached by car/scooter within 15 minutes. In Olympos itself you will find many great restaurants as well as small shops, a local bakery and very nice people. Katerina is easy to reach and responds quickly.
Note on how to get there: The drive from Karpathos town or the airport takes 1-1.5 hours and is on narrow, mountainous roads. We travelled by scooter and especially the strong wind made the journey a bit of an adventure and not recommended for inexperienced drivers :-)