The City had been stripped to a foundation of jagged, broken teeth, then left to endure ten thousand years of weathering.
Perhaps violent flooding had deposited the sand during a great turmoil of the sea, then left it to slowly age and weather through the intervening centuries.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "then left" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.