I'm completely at a loss - I live on the ***4th/top story*** of a tenanment flat in Edinburgh/the UK. Today my partner and I were out between 11am and 5pm.
When we got to our flat we noticed this unexplained build up of sand/grit on our window sill you can see in the pics.
We live at least 5km from any beach, this is the first time anything like this has happened to us.
Something else to note is the two strange circular marks that were left untouched from the dirt left?
I know this is a strange question, but this anyone ever experienced anything like this? Currently my best guess is a random dust storm that blew against our windows but that doesn't explain the circular patterning within the dirt the only other explanation is that the seagulls have put some kind of mark on our flat - has anyone here ever experienced something similiar? any thoughts would be appreciated cheers!