In the Google search console it shows me under AMP: 

Missing required structured data element for [this](https://search.google.com/structured-data/testing-tool?url=http%3A%2F%2Fwww.usa-reisetipps.net%2Fnew-york-city%2Fmanhattan%2Fhigh-line%3Fhtml-amp%3D1#url=http%3A%2F%2Fwww.usa-reisetipps.net%2Fnew-york-city%2Fmanhattan%2Fhigh-line%3Fhtml-amp%3D1)  site. 

But I can't find any missing element. Any idea?