Natural monument Vystrkov, Natural monument in Karlov, Czech Republic.

Natural Monument Vystrkov is a protected site in South Bohemia featuring a mix of wetlands, forests, and grasslands surrounding the Lomnice River. The area encompasses different habitats where local plant and animal life thrive in their natural setting.

The site was declared a natural monument by the Písek district national committee in December 1985, effective from 1 February 1986, to protect the natural boulder-strewn riverbed and adjacent banks. In the Middle Ages the riverbed was used for gold panning, and remnants of bank reinforcement remain visible. A stone bridge once crossed the river at river kilometre 9.5, and its remains can still be seen.

The name Vystrkov refers to the rocky riverbed of the Lomnice, which flows past Smetanova Lhota and its Karlov hamlet. The protected stretch runs from the 10.8 to the 8.6 river kilometre, ending at the railway bridge. Anglers of the Czech Fishing Union release common carp here each year for sport fishing.

The protected stretch runs from the 10.8 river kilometre of the Lomnice, just past the recreation facility south of Karlov, down to the railway bridge at 8.6. A metre-high weir stands at the upper end, and the river is managed by Povodí Vltavy; the banks are wooded and the bed boulder-strewn, so approach along the shore.

In the riverbed, remnants of medieval gold panning survive as reinforced bank stones, and the stone bridge that once crossed the Lomnice at river kilometre 9.5 left traces still visible today. The green frog (Pelophylax esculentus) and the common toad (Bufo bufo) are the amphibians recorded here.