Two deep ravines (Foz) with rock faces of up to 300 m carved by the Rivers Salazar and Irati in the foothills of the Sierra de Leire. The surrounding area consists of a wide valley with wheatfields, low Mediterranean countryside and Holm oak woods. There is deciduous and Common-pine woodland in the higher areas of Arangoiti (Sierra de Leire).
This area falls in the Site of Community Importance (Natura 2000 Network) and ZEPA (Special Bird Protection Area) "Sierra de Leire-Foz de Arbayún" which includes the "Foz de Arbayún", "Foz de Lumbier" and "Acantilados de la Piedra y San Adrián" Natural Reserves.Habitats
Crags, riverbank copses, wheatfields, low Mediterranean countryside and scrubland, etc.Birds
- Residents: Mallard, Red kite, Lammergeier, Griffon vulture, Northern goshawk, Eurasian sparrowhawk, Common buzzard, Golden eagle, Common kestrel, Peregrine falcon, Red-legged partridge, Moorhen, Rock dove, Common woodpigeon, Barn owl, Eagle owl, Little owl, Tawny owl, Long-eared owl, Common kingfisher, Iberian green woodpecker, Black woodpecker, Great spotted woodpecker, Lesser spotted woodpecker, Sky lark, Crested lark, Wood lark, White wagtail, Grey wagtail, Dipper, Wren, Dunnock, Robin, Black redstart, Common stonechat, Rock thrush, Blackbird, Song thrush, Mistle thrush, Cetti's warbler, Dartford warbler, Sardinian warbler, Blackcap, Long-tailed tit, Marsh tit, Crested tit, Coal tit, Blue tit, Great tit, European nuthatch, Short-toed treecreeper, Southern grey shrike, Eurasian jay, Magpie, Red-billed chough, Eurasian jackdaw, Carrion crow, Common raven, Spotless starling, House sparrow, Tree sparrow, Rock sparrow, Common chaffinch, Greenfinch, Citril finch, Goldfinch, Linnet, Common crossbill, Common bullfinch, Yellowhammer, Cirl bunting, Rock bunting, Corn bunting.
- Summer visitors: European honey-buzzard, Black kite, Egyptian vulture, Short-toed eagle, Montagu's harrier, Hen harrier, Booted eagle, Hobby, Common quail, Stock dove, European turtle dove, Common cuckoo, Scops owl, European nightjar, Common swift, Alpine swift, European bee-eater, Hoopoe, Crag martin, Barn swallow, Sand martin, Tawny pipit, Tree pipit, Rufous nightingale, Northern wheatear, Black-eared wheatear, Blue rock thrush, Fieldfare, Redwing, Melodious warbler, Subalpine warbler, Western orphean warbler, Common whitethroat, Garden warbler, Bonelli's warbler, Iberian chiffchaff, Spotted flycatcher, Penduline tit, Golden oriole, Red-backed shrike, Woodchat shrike, European serin, Ortolan bunting.
- Winter visitors: Grey heron, Merlin, Woodcock, Tawny pipit, Alpine accentor, Common chiffchaff, Eurasian treecreeper, Yellow-billed chough, Common starling, Siskin, Hawfinch.
- Passage migrants: Greylag goose, Black stork, White stork, Common crane, Short-eared owl, Yellow wagtail, Common redstart, Whinchat, Ring ouzel, Willow warbler, Pied flycatcher.Recommended observation points
- Muladar de Lumbier
- Footpath SL NA-113 "Foz de Lumbier" (4,6 km.)
- Footpath SL NA-110 "San Pedro chapel", in Usún (3,6 km.)
- Foz de Arbayun viewpoint