When I went to the UK for the first time I was blown away at how much old stuff you guys have. I was allowed to walk through a centuries old castle by myself. I could have taken home a castle rock if I wanted to. Here if something is 300 years old you can look at it from 6 feet away behind a velvet rope.
It was pretty wild to me going to a toy store that was itself older than America.
London is a very old city. One of the Wren churches has a crypt from an earlier church, so 21st Century, then into 17th century then down to something like 13th century. Another staircase down under that and you are standing in a Roman structure.
Oxford: On the main road through the centre is an old tower, the Carfax Tower, 11th century so 900 years old. You can sit in the churchyard outside that tower and have a coffee and pastry. People have been stopping for a while outside that tower for a long time. It is nice on a sunny day towards evening when the warmth of the stones staves off the chill from the rivers.
Chester: Pop into Superdrug on Northgate Street for toothpaste. Medieval chapel, wool exchange, theatre and music hall. Dickens did a reading there.