A British-style tearoom and cake shop on the Rue Saint-Romain, just behind the cathedral, with a small garden terrace looking up at the cathedral's flank. The cakes are very good — a long counter of perfect tarts and scones — and the tea list runs to several dozen.
It is touristy but unapologetic about it, and the location is hard to better. A reliable mid-afternoon pause between sightseeing.