It is not touristy and is quintessentially Greek. It island is green and pretty, with very clear waters, excellent fish tavernas, and a lively Greek nightlife. The island has produced great musicians, including the famous Hajiadakis Dynasty, and one can easily hear locals playing hammered dulcimers, bagpipes, bouzoukia and other Greek instruments.
The main port is Lakki and its capital, Aghia Maria. The somewhat ugly port is due to Italian influences during the war when they used it as a naval base. However, arriving in Lakki on the ferry at night, when the Fascisti Art Deco buildings are reflected in the gulf, is a strangely surreal and beautiful experience.
The streets of Lakki are wide and well paved. The remains of Mussolini's building efforts crumble away. Near the waterfront there's a monument to many who died in the Battle of Leros in 1943. It's not surprising that the islanders are not inclined to put any effort into preserving these buildings that were Mussolini's vision of a new Roman Empire, even through they are remarkable examples of Art Deco architecture.
There's a path from the jetty to the nearest beach at Koulouki. This beach has a taverna and campers often set up sites under the pines. Across the harbor, at Lepida, you can see the Moni Panagia atop the ruins of an old lighthouse. Further south is the fort Paliokastro on the site of an older fortification that dates from the 3rd Century BC. The nearby fishing village of Xirokambos has a nice beach. Water taxis leave from here to go to Kalymnos during the summer.
Up the hill from Lakki, a three km walk gets you to the coarse sand of Vromolithos Beach, where there are sunbeds and tavernas.
Just around the bay at Panteli there are rooms available. The village has excellent seafood eateries and a harbor full of yachts.