A removable modular slab for use in the construction industry includes upper, lower, and first and second opposing end surfaces, and a conduit extending from the upper surface to an end surface. The slab is abuttable with a second removable modular slab, having: (i) a conduit extending from the upper surface to an end surface, and/or (ii) a cavity extending from an end surface into the slab, whereby the conduits mate to form an elongate conduit through the two slabs. By access through apertures in each slab, a first joining structure is removably locatable to join the two slabs. Cavities may terminate within the second slab and only be accessible through the upper surface of the first slab. A modular surface system includes two such slabs and a joining structure to join the two slabs together.