The National Blue Trail is a national trail in Hungary, for most of its length part of the European Long Distance Walking Route E4. The route starts atop the Írott-kő Mountain on the Austrian-Hungarian border then leads across Hungary eventually ending 1,170 km later at the village of Hollóháza by the Hungarian-Slovakian border.. The name of the Kéktúra is a reference to the marking of the path itself: it is a horizontal blue stripe on a white rectangle. All segments of the trail are freely accessible to the public; no fees have to be paid or permits obtained, there is only one ferry to take over the Danube between Visegrád and Nagymaros where you have to purchase a ticket. Although to have an official completion, you have to purchase a stamping brochure from MTSZ, the organizer of the trail.

Sirok is a village in Heves County, Hungary, in the Mátra mountain range, beside of the Tarna River. As of 2022 census, it has a population of 1625. The village located 18.9 km from Eger, the capital of the county and beside of the Kisterenye–Kál-Kápolna railway line, 23.9 km from the main road 3 and 24.5 km from the M25 expressway. Kőkút is located 5.2 km southwest of the center of the village, which is an other inner area of 185 people with its own railway stop. Next to the road leading there is Sirok's own railway stop, 3.5 km from the center. Although the settlement has its two own railway stops, public transport on the railway line ceased on 3 March 2007. The closest train station with public transport is in Eger 20.5 km away.