This paper presents the results of shaking table tests of a system exhibiting negative stiffness. As the system uses dry connections, it is suitable for precast construction, and it can be easily disassembled and re-used. The specimen was composed of four restrained rocking columns and a slab. The reinforced concrete columns were protected by steel jackets at both ends and restrained by an ungrouted tendon in series with disc springs. The tendons were anchored at the bottom of the columns and above the slab. The intention of the design concept is to reduce the size of pile foundations, which, in conventional bridges, can comprise a large portion of the total reinforced concrete of the project and is often governed by seismic loading. Hence it saves material and is a contribution towards sustainable design. The system was simultaneously excited in the longitudinal, transversal, and vertical directions by 181 scaled real seismic records. During the tests, it could be observed that the columns not only rocked, but also twisted and slid. The only damage noticed during the first 180 excitations was abrasion on the edges of the steel jackets. The last excitation (#181), however, caused collapse. The tendons unexpectedly failed at a load less than 50% of their capacity (provided by the manufacturer), due to failure of their end socket. This failure highlights the importance of the tendons for the stability of the system at large displacements. The response of the system is discussed in detail presenting the main characteristics of the system