Abstract: A lightweight ballistic shelter comprising mutually connectable modular panels of two sizes only (8, 7, 6). Each panel (8, 7, 6) of the shelter structure is connectable to any other panel of the shelter system thus allowing protective structures of different sizes and shapes to be assembled therefrom. The shelter is assembled from planar panels of which at least one (6) has the shape of an equilateral triangle and at least another one (7) has a square shape. The shelter system also includes coupler means (4, 5) for connecting the modular panels (6, 7, 8) with each other.