Eretria follows, which is an unappealing resort with a population of 5000. Ancient Eretria though, is of interest, especially its excavations which revealed a theater with steps leading down into an underground chamber used for rapid exits and entrances; and ruins of a gymnasium and sanctuary.
There is also a House of Mosaics from the fourth century BC which can be viewed if one asks the guard from the museum. The latter is open Tues-Sun 8am-2:30; 1.50 euros). Right from the museum, during battle and smitten by Eros, Theseus is abducting a smiling Antiope Queen of the Amazons. There is also an agora and a temple of Dafniforos Apollo closer to the town. 11km west of Eretria on the coast there is a very nice campground (Milos Camping: 2211 060 460; fax 2211 060 360).
There is a tourist complex on an islet linked to the bay by a causeway and a nicer resort farther on at Amarynthos with a good waterfront with many restaurants. The fishing village of Karavos, near Aliveri, is also nice. From there the road heads east and inland, passing through Lepoura, and after that the landscape becomes much more appealing. There are nice beaches via sideroads if you have a car, at Kalamos and Korasidha. At Avlonari,to the north, you will find the basilica of Ayios Dhimitrios (fourteenth century). The town itself boasts a Venetian tower that sits up on a hill and the slopes of the town have some nice neoclassical houses (but no rooms). The chapel of Ayia Thekla, on a side road nearby, features frescoes (or pieces thereof), and there are other chapels at Ayios Nikolaos and Ayia Anna. At the coast, you can swim in a river mouth at Stomio, and there is another river before Kymi, at Platana.