I will give an overview of gravitational wave research covering the phenomena itself, instrumentation and the (recent) first observations. Next I will introduce the Einstein Telescope (ET) project: the next-generation observatory and the steps we are taking to explore the South-Limburg border region as a possible site. I will conclude with a short introduction of the ETpathfinder laser-interferometer R&D laboratory we are now realizing in Maastricht to develop the new technology envisaged for ET.