Taxonomy has it's own folder within the content tree in Sitecore and can be found here: /sitecore/content/TaxonomyHub
The hub contains many taxonomy folders used to categorise all site pages which can be selected in the parent item of pages. The hub also contains the tour operator categories
To add a new taxonomy folder, right-click on the Taxonomy hub > Insert > DatalayerTaxonomyField
To add a new taxonomy field, right-click on the Taxonomy folder > Insert > DatalayerTaxonomyFieldItem