The fashionable fortified town of valkenburg nicknamed marltown is situated in the hilly dutch province of limburg you will come across the warm yellow colour of the marlstone in the town itself as well as in its beautiful surroundings the towns attractions and places of interest such as castles museums fun parks caves a holland casino the health resort thermae 2000 and the castle ruins are well worth a visit cosy shops pavement cafes the little river geul and monumental buildings