The city where "Confessions of an Opium-Eater" was published.

Oxford
Oxfordshire recorded its highest number of drug-related deaths since 2002 last year, figures show.
The Royal College of Psychiatrists called on the Government to “wake up” following years of cuts to addiction services, which it said have fuelled a record number of deaths across England and Wales.
Office for National Statistics figures show there were 42 drug-related deaths recorded in Oxfordshire in 2020.
This was up from 32 the year before, and the highest figure since 2002.

The area where "Kubla Khan" Poem was written by Coleridge.

The city is Edinburgh where the incidences in the book were happening.

Edinburgh
National Registry of Scotland figures released today indicate that there were 109 drug-related deaths in Edinburgh in 2021. This is an increase on previous years and the highest ever recorded in Edinburgh. The numbers reflect 109 tragedies for individuals, families and our community.
Source : https://www.edinburghadp.co.uk/2022/07/29/drug-related-deaths-in-edinbu…

The city where "Junky" by Burroughs was published.

London 1800s