Lostun (1,653 m a.s.l.) is a wild and rewarding summit in the Chyvchyn Mountains of the Ukrainian Carpathians, within the Marmaros massif. With open alpine meadows at the top and dense forests covering its slopes, it offers a genuine off-the-beaten-path Carpathian experience for those willing to seek it out.

The lower slopes and flanks of Lostun are blanketed in thick forest, giving way to open polonynas — treeless highland meadows — near the summit. The western flank is particularly steep and demands respect. To the northwest rises Chyvchyn (1,766 m), the highest peak in the Chyvchyn Mountains, while Maly Lostun (1,595 m) sits to the south. The views from the top across the surrounding ridges are well worth the effort. In spring the meadows burst into fresh green, summer brings wide-open panoramas, and autumn transforms the forests into a blaze of colour. The Ukrainian-Romanian border passes close to the southwestern slope, adding a quietly dramatic edge to the setting.

• Village of Burkut (nearest settlement, to the northwest of the peak) — no officially marked trails; approach via forest paths through the slopes; demanding terrain, mountain experience recommended.

• The Ukrainian-Romanian state border runs near the southwestern slope — do not approach or cross the border zone.
• An old mine shaft is located on the mountain — entering it is dangerous.
• The Vysyache Boloto (Hanging Bog), a protected hydrological nature monument, lies to the north of Lostun and is worth a visit on the same trip.

The Popadynets stream, a left tributary of the Black Cheremosh river, has its source at the southwestern foot of Lostun — a small but telling reminder of how these high Carpathian meadows quietly feed the rivers of Eastern Europe.