ON A TERRACE that overlooks the River Thames at Richmond there is a curious souvenir of the past. The so-called Fish Marker Stone was dug up in the 20th century. It is named thus because there is a carved fish or sea creature on top of it. Now no longer visible because it has worn away, the stone’s inscription bore the words “To Westminster Bridge 14 3/4 miles”. The stone is believed to have marked a fare stage for boatmen carrying passengers along the river.