I’ve recently added a new feature to https://map.atownsend.org.uk , prompted by the dreaded lurgi that is affecting everyone at the moment - the ability to show pubs with either outdoor seating or a beer garden.
Outside seating is shown like this:
with a black line at the bottom right of the icon.
Here’s a beer garden:
with a green underline instead of black
For the rest of the map legend see here.