Hamilton Mausoleum is a mausoleum located in Hamilton, South Lanarkshire, Scotland. It was the resting place of the family of the Dukes of Hamilton. Built in the grounds of the now-demolished Hamilton Palace, its high stone holds the record for the longest echo in the world, taking 15 seconds for the sound of a slammed door to decay. There were recent claims that this record had been broken at the Inchindown oil storage tanks in the Scottish Highlands, however this turned out to be a reverberation rather than an echo. It is now closed to the public.