Popinolashki waterfall, Natural waterfall in Lilyanovo, Bulgaria

Popinolashki waterfall is a cascade in the Pirin Mountains where water plunges down a steep rocky face for about 15 meters. The fall originates from the Bashliitsa River and drops through a forested area surrounded by the convergence of several mountain streams.

On 11 October 1965 the waterfall was declared a natural landmark under the name "Waterfall of the Sandanska Bistritsa River". The designation covers the fall on the Bashliitsa, about a hundred metres above its confluence with the Sarchaliitsa, where the two streams form the Sandanska Bistritsa.

The waterfall lies in the Popina laka area, on the Bashliitsa just above its confluence with the Sărčalijca; together they form the Sandanska Bistrica. The nearest village is Liljanovo, and the Jane Sandanski hut is 5–6 minutes away, so the fall is a stop on walks from the hut.

The waterfall can be reached by following marked trails that start from the village of Lilyanovo in the mountain region. The hike passes through forest terrain, so sturdy footwear and attention to the path are advisable.

The waterfall stands about a hundred metres above the point where the Bashliitsa meets the Sărčalijca; together the two streams give rise to the Sandanska Bistrica. The nearest village is Liljanovo, and the Jana Sandanski hut is only five to six minutes away.