An interlocking modular mat having four sides has female connectors on two sides and male connectors on the other two sides so that the modular mat can interlock with an adjacent mat and its connectors. The modular mat is configured with a plurality of structures surrounding a periphery of a top portion of the mat. The plurality of structures in combination with an underside of the top portion of the mat form a cavity. A sponge insert is configured to fit in the cavity and have a height such that a portion of the sponge insert extends from a bottom side the mat body. With the sponge insert extending beyond the bottom side of the mat body, the sponge insert bottom face generally become the supporting bottom of the modular mat to provide a more cushioned feel for a mat user.