I suppose some of us know that here is an inlaid swastika in the floor of Upminster Bridge Station. I didn't until about a week ago.

The only other permanent swastika I could think of is on the side of the Indian High Commission at Aldwych, right at the end of Kingsway.

I remember a small Indian shop near me had a hand-written NO SMOKING sign that was covered in hand-drawn swastikas, not meaning "this rule will be rigorously enforced" but simply, "for health".