Le Musée l'Orangerie had been closed for several years.
Initially due to renovations, then ancient stone walls were discovered during the excavations in 2003.
Renovations were halted until the age of the underground structure could be set.
Archaeologists determined the "ancient walls" were part of Louis XIII's third and last set of walls built during the period of 1632-1637., and not so ancient, which allowed renovations to continue.
With the renovations complete, the museum open again this spring, but several years of closure meant several hundred metres of queue.
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