‘It’s like hiding an elephant’: €171m feat of engineering creates museum under Dutch palace

Paleis Het Loo was built as lodge for man who became William III, king of England, Ireland and Scotland from 1689

At first glance, King William of Orange's palace seems just as it was in the 17th century - a handsome Dutch baroque building set along three sides of a courtyard seemingly pockmarked with rain puddles.

But underneath the courtyard, an injection of engineering expertise costing 171m (151m) has created an extraordinary modern museum, opening next week.