Petra is 5km south of Mithymna. It has a long sandy beach with shade. The huge rock looming over the village is topped by Panagia Glykophilousa (The Church of the Sweet Kissing Virgin). The climb up is exactly 114 steps. Just to the east, the village of Petri is a nice spot for island viewing and has a charming traditional feel.
The western side of the island is drier with fewer towns. Sappho's birthplace, Eresos, is 90 km west of Mytilini. The nearby beach is Skala Eresou. Eresos is a popular destination for lebians who want to honor the poet Sappho. (The whole island, not just Eresos, is very gay-friendly.) The pertrified forest of Lesvos is on a barren hillside on the far western end of the lsland. Past the beach at Skala Eresou is the village of Sigri, close to the ancient tree trunks referred to as the petrified forest. Western Lesvos draws birdwatchers in the spring, and this is where the island's famous horses are bred.
Mount Olympus dominates southern Lesvos. (There are 19 mountains named Mount Olympus in Greece.) On the mountain's northern side is the large village of Agiasos. Artisan workshops are plentiful here. This beautiful hill town holds a church with an icon painted by St Luke and a couple of worthy museums, too. On the coast, Plomari has a good beach and a traditional feel. This region has a number of good treks, called Olive Trails because you walk through various groves of trees, especially olives. An hour's walk west of Plomari is Panagia Krifti, a church in a cave near a hot spring. The Museum of Natural History at Vatera on the south coast has fossils and of elephants, mastodons, giraffes, rhinoceros, hippopatamus, deer, tortoise, snails, fish, and horses found in the area.
Most of the mineral springs are in old whitewashed bathhouses dating back to ancient times. Loutra Yera's springs contain radium. The springs are quite hot at Polyhnitos. The waters at Lisvorio are similar. At Eftalou the water is perfectly clear and an ideal temperature. There is a petrified forest at Sigri as well as thermal springs.
There are good trekking trails in both the north and south. The trails are easy to find and follow. They can be taken in sections and broken up over several days. Although there are many trails, the main trails are Vatera-Yera, Petra-Lapsarna, Kapi-Sykaminia and Segri-Eresos. There are also good treks in the olive growing region around Plomari, with the Skopelos-Karionas-Kastelos-Trigonas/Plagia day trek being the most popular.