The Monastery of the evangelist St John the Divine sits on top of a prominent cliff bluff and seen from virtually everywhere on the island. The monastery's high grey walls are fringed the white cube houses of Chora. It looks more fortress than monastery, and that was part of its purpose, to keep monks and villagers safe from attacks by marauding pirates.
That is also the reason why, despite its large size, it has only two doors in its 15-metre high walls. There is even a balcony from which molten lead could be poured down on any attackers trying to storm the main gate.
Building began in 1088 under the direction of the monk Hosios Christodoulos. The interior is a multi-levelled complex with interior courtyards, colonnades and narrow corridors.
Inside, the visitor first enters the cobbled courtyard lined with four chapels. To the north, the monk's cells are constructed around the central nave or catholikon, in the Byzantine style and an astonishing temple built in 1820 by 12 craftsmen and containing the abbot's chair and many beautiful icons.
Indeed many of the monastery's icons are beyond price, as indeed are many of the treasures inside. Notable is the sacristy, built by the bishop Nikiforos of Laodicia with a large icon of the revelation, dating from 1625, and an 11th-century icon of Agios Nikolaos, as well as jewels, gold and silverware donated by rich Patmians.
The historic library is one of the most important religious libraries in Greece, if not the whole Christian world, with 900 rare manuscripts from the 15th and 16th centuries, more than 20,000 unique books and around 13,000 other manuscripts and codes.
Arki and Marathi are part of a small clutch of islands in the Dodecanese group, north of Lipsi and east of Patmos and a popular destination for day trip boats from Patmos, Leros and Lipsi. They are on the main ferry route from Samos to Kalymnos and gets about three boats a week calling in with visitors and supplies. There is also a twice-weekly boat from Patmos.
Arki is about eight nautical miles from Patmos and has about 50 permanent residents, a harbour, a couple of small beaches, four tavernas and a minimarket. Arki harbour is in a deep bay, well protected from winds. Most islanders live close to the dock and survive by fishing, goat herding or helping run the tavernas.
Arki is virtually treeless: a dry, rocky landscape with little vegetation apart from olive trees and some hardy shrubs. On the hill overlooking the harbour are the ruins of an acropolis, barely more than a pile of stone now. The best Arki beach is at Tiganakia in the south. It's tiny and rocky, but the view across the bay to nearby islets is idyllic.
Day-trippers arrive from mid-June, and by August the beach can be crammed every day. At the northern shore is a cave with stalactites and stalagmites, although it's not easy to find among the olive trees.
Arki may be small, but Marathi is even smaller, although it does have the best beach. There are a couple of dainty harbours, three tavernas, a few houses for the 40 or so islanders, a beach and some goats. There are no villages on Marathi, just the long, sandy beach with a taverna at each end and one in the middle. Marathi has a few rooms to let, but it's best to arrange to stay on Marathi before you arrive – if they are full you get to sleep on the beach.