No special permit required to visit the area, please make sure you keep your ID with you as the border guards may all of a sudden want to verify your identity should you seem oversuspicious. Don't swim in the river. Barbed wire fence starts a little further upstream, past the border marker pole #88. Use the toilet downstream should you fall into emergency. The cache is a small plastic bottle preform sitting in a juniper bush immediately by the road.
Depending on which route you choose from the main paved rode you may need to cross a tiny Sosnovsky Borsch grove. Make sure not to touch the plants with a bare skin.