An indoor gymnasium or training hall in Kostinbrod, Bulgaria, is depicted, showing approximately eight children and youth engaged in a physical activity

An indoor gymnasium or training hall in Kostinbrod, Bulgaria, is depicted, showing approximately eight children and youth engaged in a physical activity. The space features light orange-painted walls, a floor composed of interlocking foam mats in alternating teal/green and light pink/orange sections, and a ceiling with multiple square fluorescent light fixtures, some protected by wire grilles. On the left wall, a row of windows with white radiators underneath is visible. The far wall displays a basketball hoop with a black backboard. A wooden wall ladder is affixed to the right wall. Of the participants, five are dressed in white martial arts uniforms (doboks); at least two of these uniforms are accented with yellow belts. Two boys are wearing dark casual athletic t-shirts and sweatpants. One boy in a light blue t-shirt and black sweatpants with a white stripe runs barefoot in the foreground. Several individuals are positioned in wide, low stances, indicating stretching or martial arts postures. These include two girls and a boy on the left, a smaller child in the center, and a boy in casual wear further right. In the mid-right foreground, a girl in a white dobok is kneeling on the teal mat. Adjacent to her, a girl in a white dobok with a yellow belt is lying on her left side on the teal mat, facing towards the kneeling girl. The overall scene suggests a structured martial arts or fitness training session.