What's the best format for a e-commerce URL product page

[philwill]

We have over 2000 non branded experiences and activities sold through our website.  The website is having a face lift with the a new look and a stronger focus on SEO.  As part of this, I am keen to establish what the best practice is for product based URLs.  I've researched the market and come up with a few alternatives that are used:

domain/category/subcategory/activity_name

domain/activity_name/category/subcategory/activity_reference

domain/generic_term/activity_reference/activity_name

domain/category/activity_location/activity_name

Activities are location based but the location can change (say once every 2 years).  Activity names, category, subcategory and activity_reference rarely change.

Are there any thoughts/ research on the best method?  (If there is one)

Many thanks in advance for your insights.

[EGOL]

I am not answering because I don't know the amounts of traffic generated by your categories, locations, references, activities, etc.

So, I would be doing lots of KW research.

Also, I would be using hyphens instead of underscores in the URLs

[philwill]

Without considering other factors (links, domain age etc), your understanding certainly ties in with one of the front runners in the industry who use

domain/activity_name/category/subcategory/activity_reference

[EugeneF]

It has been my understanding that words in a URL closer to the left are more important.  I would look at search volumes and try to use the same word orders as the higher search volume keyword phrases.