As a consequence of the unique positioning and 3,5: 1 plan ratio, the proposed twin buildings (103 m) for the latest expansion of the European Court of Justice (Luxembourg) led to the commissioning of a comprehensive set of wind-tunnel tests. Experimental testing and numerical analyses showed the buildings to be susceptible to unacceptably large wind-induced accelerations at the top levels. To mitigate these vibrations, a Tuned Liquid Damper (TLD) array is proposed and designed for both the buildings.With an optimal design of the TLD array, total maximum reduction in top-level acceleration is found to be in the range of 35-40%, reducing building accelerations below acceptable limits for human comfort. Experimental verification of the performance of the dampers is undertaken through 1: 2 scale shaking table tests.