Specially designed wooden souvenir "VR4D KRK" is used in conjunction with the mobile application "VR4D KRK", in the way when the application is launched on a mobile device, the device's camera is directed towards wooden cards, after which a three-dimensional relief appears on the screen of the mobile device. the outline of the island of Krk with inscriptions of individual places and video representations of the same, and the tourist attraction Biserujka Cave in a three-dimensional virtual form and a visual representation of its interior.