Mathraki is a verdant, long and narrow island, the smaller and most southern of the Diapontia Islands, at a distance of 4 nautical miles from Arillas. The tourism development of the island is minimal and its few inhabitants are mainly occupied with oil production and fishing. A single road paved with asphalt leads you to all the main locations of the island. You can also walk it from end to end. It will not take you more than 4 hours. You will reach Mathraki by boat from , with frequent schedules during summer. The small port of the island is Plakes where, the few touristy lodgings of the island are situated.
In Mathraki you can go on excursions to the settlement Benatika where, two roads begin and traverse through the whole island. The biggest part of the north-eastern side of the island is covered by the sandy beach of Portelo with its clean waters that deepen smoothly, while the north-western shores in Mathraki are considered a paradise for divers and for those who like to fish underwater. In the southern shores you can swim in Apidies where, you will enjoy a lovely sunset.
A popular explanation for the name of the island states that many years ago, Mathraki had been burnt and it was named after the “athrakia” (charcoal).