The San Martin bridge (Toledo), was originally commissioned in the 14th century by Archbishop Pedro Tenorio, and, according to local lore, the architect who built it had made a big boo-boo. He realised a few days before the inauguration that he had miscalculated the bridge’s load bearing capacity.
Riddled with anxiety, he told wifey of his fears that once the scaffolding was removed, the structure would come tumbling down. Said wife, clearly more of an action person than a worrier, went out at night and burnt the whole thing down, giving her husband the chance to do the job again, and this time properly.
(Text from ladyofthecakes.wordpress.com)