A modular panel and system of panels provides an aesthetically pleasing covering for an interior surface of a building. The panels include a skin, which in some embodiments includes a backing. The panels have a three-dimensional relief and can be abutted together to form a system of panels forming an integral three-dimensional pattern, a perimeter of the panels having a plurality of interlocking mechanisms positioned such that when the interlocking mechanism of the panel engages the interlocking mechanism of at least one adjacent panel, the three-dimensional pattern seamlessly continues in all three dimensions, from the panel into the at least one adjacent panel.