It is located at an altitude of 180 - 200 m.a.s.l. in the western part of Khustsko-Solotvynska Valley, on the ancient terrace of the Tysa river. The protected territory, with the area of 257 ha, lies in a flat site of the Khustets river flood-plain. Besides natural watercourses, there are also artificial channels of land-reclamation system in the massif’s territory. The climate is warm, damp. According to the data of Solotvyno meteostation (272 m.a.s.l.), the average annual air temperature is 8,5 degrees, in January - 4.0, July - 19.5 degrees. The annual amount of precipitation is about 850 mm. The sod-gley heavy - and medium loaming soils, which were formed on the ancient alluvial deposits, prevail here.

The "Valley of Narcissi" - a unique botanical unit, where the largest in the Middle Europe seat of narcissus angustifoliate (Narcissus angustifolius) is protected. This Middle European high mountain species is spread in the Alpes, the Balkans and the Carpathians at an altitude of 1100 - 2060 m. Its population in this flat locality is preserved from the postglacial period and has a relict character. There are several communities of this species, growing in the massif’s territory: Narcissus angustifolius + Sanguisorba officinalis + Anthoxanthum odoratum, N. angustifolius + Festuca pratensis + Holcus lanatus, Juncus conglomeratus +Filipendula vulgaris + N. angustifolius.

More than 400 species of plants, among which are such rare species as: Achillea salicipholia, Dactylorhisa fuschii, D. majalis, Erytrhonium dens-canis, Gentiana pneumonanthe, Gymnadenia odoratissima, Iris sibirica, Orchis coryophora, O. laxiflora, Potentilla alba and others, grow in the "Valley of Narcissi".

The faunistic structure of the "Valley of Narcissi" greatly differs from other protected sites. The animals of water-meadows of the Transcarpathian plain are represented here. Among birds prevail such species as: whinchat (Saxicola rubetra), yellow bunting (Emberiza citrinella) and whitethroat (Sylvia communis). The typical species of the more humidified places are: corncrake (Crex crex) and sedge warbler (Acrocephalus schoenobaenus). Such species as pheasant (Phasianus colchicus L) is found in shrubs, along the Khustets river. Rarely, one can found a penduline tit (Remiz pendulinus) here.

The typical amphibia of the "Valley of Narcissi" are: edible frog (Rana lessonae), common toad (Bufo bufo L), smooth and warty newts (Triturus vulgaris; T. cristatus). Among the reptile species one can found a grass snake (Natrix natrix) and a sand lizard (Lacerta agilis). Fauna of mammals is represented by common vole (Microtus arvalis), striped field and harvest mouses (Apodemus agrarius; Micromus minutus), muskrat (Ondatra zibethica), European hare (Lepus europaeus) and other species, untypical for the mountain massifs of the reserve. Rich ichthyofauna of the Khustets river numbers nearly 20 fish species.