Zelenci Nature Reserve

Zelenci is where the Sava Dolinka comes out of the ground, and the effect is unusual enough to have made it a small nature reserve: a shallow pool a couple of metres deep whose bed is white chalk sand, with springs rising through it so that fine sand boils up in slow plumes. The colour is a strong green that comes from the light on the pale bed rather than from anything in the water. A boardwalk crosses the marsh around it to an observation tower.

What you actually see

• The spring plumes - sand lifted in slow boils where the water enters the pool.
• The colour - a strong green produced by light on the white chalk bed.
• The boardwalk - a raised walk over the marsh and reed beds around the pool.
• The observation tower - a wooden tower giving the view down into the pool.

When to go

Year round; the colour is strongest under midday sun and weakest under cloud. Winter brings frost patterns and fewer visitors. Summer weekends bring coach parties from Kranjska Gora.

Honest expectations

It is small and the visit is short; twenty minutes covers it. The green is much less dramatic on an overcast day, which the photographs never show. Swimming and entering the water are forbidden.

Nearby

Kranjska Gora is east, and Planica is south.