Complex sentence: A memorial garden was opened on the site of Pantglas Primary School, which was destroyed during the disaster, the park was partly opened by the Queen, accompanied by the Duke of Edinburgh on her visit to Aberfan in 1974.
Split into simpler sentences: A memorial garden was opened on the site of Pantglas Primary School, which was destroyed during the disaster. The park was partly opened by the Queen, accompanied by the Duke of Edinburgh, on her visit to Aberfan in 1974.